Exciting at first about how convenient it is. Unfortunately, the excitement didn't last long as I expected for a Microsoft keyboard. The keys started losing their functionality one after another, either needing to be pressed five times or not working at all.

Pros:
+ Tremendous ergonomic design for blind typists (or those who want to learn)
+ Very convenient that the numeric keypad is separate, so I had it on the left side, which helped me with my work - left numeric keypad and direct access to the mouse on the right without my hand having to travel.
+ Battery life

Cons:
- The keys were not durable at all. Within a year, they started having poor contacts, especially the numeric keypad. UNACCEPTABLE for a 100+ keyboard. So far, I've only seen this in <10€ keyboards.
- The mouse is not ergonomic at all. (I got the Logitech Master 3s and I am extremely satisfied).
- It's not Bluetooth, so you have to be careful with the USB receiver not getting lost and taking up a USB port, especially for laptops.

I come from the sculpt comfort, which I changed for 2 reasons, initially because it is huge and does not leave space for the mouse, and secondly because of the excessively long key travel. For these 2 reasons, I got the sculpt ergonomic. I can say that although the build quality is somewhat controversial, it is truly ergonomic, no strain on the wrists, it is beautiful, sturdy, completely functional (it even has keys to switch virtual work surfaces that you would normally need a touchpad for), small in size to accommodate the mouse, with a very good feel on the keys, which have the correct travel. Typing is done with fewer mistakes compared to the sculpt comfort, the keys have the correct spacing between them, as strange as it may seem from the photos.

The only negative is that the arrow keys, Home, End, PgUp, PgDn, Insert are placed randomly and you have to look at the keyboard to press them correctly. The mouse wheel is not as good as it used to be, this has to do with the quality (at Microsoft, you pay for ergonomics, at Logitech, for build quality).

The mouse has amazing ergonomics, as much as I didn't believe it from the photos.

Overall, I am fully satisfied, although I would be willing to pay more to have this ergonomics with a better build quality of the keyboard and mouse mechanism.

Edit: The MS sculpt comfort mouse is ergonomically better in my opinion despite its design flaws.
Edit2: It died in the 6th month, so the internal build quality is worse than expected

Yesterday I received it. Excellent keyboard feeling.
It takes time for the hand angles to get used to the water adjustment.

The numeric keyboard is extremely convenient for me because it is separate, due to the software I use.

The mouse is different, but very convenient.
Of course, I cannot judge its durability over time, but the build quality is excellent.
The batteries were charged from the box.

Small things like magnetic covers for the battery compartments make the difference.

EDIT:

18 months later, I bought my second set.
In the first one, and while it was still under warranty, the scroll on the mouse broke.
The set was returned to the supplier, who sent a different, inferior set worth around €60 instead of the same one, claiming that the model I had was discontinued and no longer available.
For as long as the procedures took, I worked with a simple keyboard and mouse, and I found it extremely difficult.
Today I received the new set and once again found my balance.
Kids, there's no doubt, the keyboard feeling is simply amazing.
Even if something breaks again, I will buy it again with my eyes closed...

After 10 months of use:
1. Both the keyboard and the mouse have an amazing feel and are very comfortable even after hours of use.

2. I find it a bit useless to have the numpad separate, so I ended up keeping it permanently next to the keyboard as if it wasn't separate and dragging it along with the keyboard every time I move it, but it's not a major issue.

3. The mouse has a very nice feel and I find the button on the thumb that acts as a Back button and the scroll wheel that "clicks" left and right and scrolls the horizontal bar in Windows applications very convenient.

On the negative side:
1. The keyboard cushion has started to fade and does not recover.

2. Sometimes the left click does not respond and either does not click or double-clicks, which can be very annoying.

3. In the top row of the keyboard (Esc, F1 - F12, Calculator, ...), the keys are "clicky" (like an old mobile phone) and the ones I use most frequently tend to stick and sometimes remain pressed, requiring me to move them with my finger to return to normal.

Given its price (100€), I find the issues with the mouse and the special keys unacceptable. Otherwise, I am very satisfied.

Edit 5/2/2020
I deducted another star because the mouse now has a mind of its own when it comes to when you can left click and it will also push me to spend extra for a new mouse.

I have been using Microsoft ergonomic keyboards for over 10 years (ergonomic 7000, 4000, etc.). It is the best ergonomic keyboard that the company has released and one of the best overall. Because my work involves a lot of text editing, I have never had any issues with wrist strain using Microsoft ergonomic keyboards, including this one.

In terms of positives: the key press is excellent, the design is original and top-notch. It has a compact size, perfect for small offices or limited space. Personally, I don't use the detachable numeric keypad, so I find the smaller length of the keyboard extremely convenient. Its ergonomic design and support are ideal for protecting the wrists from strain, especially when typing for long hours. The laptop-style keys are quiet, in fact, I would say they are some of the quietest I have used. The key spacing is small. Compared to previous keyboards, I have noticed a significant difference in typing speed, key press force, and noise. I am familiar with touch typing, and with this keyboard, I can type faster, make fewer mistakes, and it is definitely quieter. It takes two small AAA batteries, which definitely last for over a year. It doesn't have an on/off switch, but it doesn't really need one.

As for the negatives: it doesn't have LED backlit keys. Since I am familiar with touch typing, this doesn't bother me because I don't look at the keys while typing. Due to its ergonomic design, it is targeted towards those who are familiar with touch typing. If you look at the keys while typing, it's better to look for something else because you will get confused with this keyboard. It is not a keyboard for gamers, but it is almost exclusively aimed at people who type a lot. The arrow keys are not as convenient to use and I often confuse them with other keys because they don't stand out and there is no spacing between them and the other keys, they are somewhat cramped. There is no indicator or light on the keyboard to show when the CAPS LOCK is pressed. A significant negative is that the wrist support cushion, which used to be leather in previous Microsoft ergonomic keyboards, is now somewhat fabric-like or suede, which results in it getting dirty from hands and friction. If you don't clean it constantly with, for example, wet wipes, it starts to look faded in the areas where the wrists touch. Microsoft provides minimal support for its keyboards on Mac computers, therefore, without drivers, some secondary functions and keys do not work on Mac computers. For the same reason, you cannot customize the functions of various keys on Mac. In general, it has very limited customization options. Another downside is that it doesn't use Bluetooth, only the Microsoft receiver at 2.4 GHz. Lastly, the F1, F2, etc. keys are not regular-sized, they are smaller and have a different shape, and they will likely start to stick after a certain point. Essentially, they are not keys but buttons. Compared to most keyboards, they are small and not user-friendly. If you use them frequently, their use may become annoying. I am starting to have a similar issue with the ESCAPE key (same shape as the F1, F2, etc.), which often gets stuck.

I don't use the mouse and I don't have a clear opinion on it because I have a different one from Logitech, but I can confirm that even though it is large, it is ergonomic and comfortable. Overall, it is a honest and premium product that justifies its high price compared to other ergonomic keyboards, especially since it includes a mouse. I have been using it for three years already and I am completely satisfied.

UPDATE 21/3/2021: After 5 years of use, this keyboard still accompanies me in my daily life. It remains one of the best ergonomic keyboards that have been released, but now it faces stronger competition (Logitech Ergo K860) as it used to be almost unrivaled. It has encountered some minor issues, mainly with the ESCAPE key, which often gets stuck and requires me to press it a couple of times a day at least to unstick it. The wrist rest has not gotten dirty (because I clean it regularly every 2-3 days), but it does show signs of aging. It remains durable and comfortable, without fading in certain areas, but its texture has changed somewhat due to friction, giving it a rubbery feel rather than a matte fabric feel. The fabric surface shows signs of wear, but not where the hands rest (as one would expect), but rather at the lower edge. The truth is that it requires quite a bit of attention as it gets easily dirty. Occasionally, I notice some very minor typing delays, which are related to interference in the 2.4 GHz frequency. It is not something widespread or common, nor is it something rare. Due to frequent use, I believe that the sensation of certain keys is gradually affected, which is expected but not to the point of being bothersome. I believe that it was worth the money, and I have not regretted it for a moment. It has been a faithful worker, but now I want more from a keyboard (Bluetooth, ability to connect simultaneously to a laptop, support for Mac computers, key customization, better drivers), so I see myself looking for a replacement.

Amazing keyboard. I don't think it's for gamers (I'm not) because the keys have more of a laptop keyboard feel (not as short of a travel distance but something in between compared to classic desktop keyboards). The design is great (of course, it's a matter of taste) but I think Microsoft did a really good job in everything that doesn't just have to do with appearance. From the magnetic ports to the separate numpad that you can move to the left or right of the keyboard or put it in the drawer.

The only downside is the mouse that it comes with (and unfortunately, it affects the price) which for me is terrible and I have put it aside.

edit 30/01/2015 I was forced to use the mouse lately. It's usable and works OK, it's just not particularly comfortable for long hours of work on the PC. The forward button is greatly missed.

edit 01/01/2017 I bought it again (just the keyboard, without the mouse) not because the first one broke but because I had burned the "leather" with a cigarette and I couldn't stand looking at it like that. I was afraid that Microsoft would stop producing it and I wouldn't be able to find it later on....