I made this review on the same device WITH a keyboard and simply transferred it here for the information of potential buyers, the purchase was made in April 2018.

SCREEN.
The screen of the Surface Pro 12.3 is the best I have personally seen so far. (it is the fourth tablet I have) it has a high resolution (2736 x 1824, with 267 pixels per inch) with a 3:2 aspect ratio) but also high brightness.
At 50% brightness setting, it covers most lighting conditions, even in strong sunlight if you are in the shade.
I did various tests to see how it looks from the sides, how it looks diagonally from above or below.
And of course the best test for me, how it looks when it is sunny, that was my problem with the previous (last) tablet I had and I was constantly looking for shaded spots.
The test was done with strong sunlight and with the sun's rays hitting directly on the screen, I can easily see and read everything.
This was also the main reason why after a lot of research I ended up with this tablet.
Note that not only did I not try to hide the reflections and mirror effect of the screen, but I tried to highlight them as best as possible.

KEYBOARD.
Very good! Especially for those like me, who have large hands, I did not measure the dimensions of the keys, but I have the feeling that they must be almost like a regular keyboard, only thinner in thickness, something that does not create a problem during typing.
The Caps Lock and Fn keys have built-in LEDs that light up when active.
The base is made of a metal alloy and is quite rigid and compact, so as not to create elasticity or vibration problems during use, while at the same time it is quite light.
The feeling of suede on the keyboard is also very nice.
Another thing I liked is the three-level adjustable brightness of the keys, according to each one's preference, as well as the automatic shutdown for battery saving after 20 seconds.
Of course, as soon as you touch a key, the letters, symbols, and keys light up immediately.
It also provides very good protection for the screen during transport.
Finally, it weighs only 295 grams.

BATTERY.
Here too Microsoft managed and did a very good job.
With internet browsing and watching a few videos, it consumes the battery at a rate of about 10 to 12% per hour. Depending on the brightness setting.
Charging is done at a rate of about 33% per hour.
However, what annoys me and is unacceptable for a tablet of this price, quality, and name, is that when it is closed you cannot see how much longer it will take to reach 100% charge, it has no indication in percentages or with any symbol, as other much cheaper tablets have, nothing.
You simply connect it to the power and calculate how empty it is, in how much time it will fill up.

QUALITY.
I cannot say anything negative because there simply isn't anything like that.
The device is very well made and everything (switches and ports) are in the right place.
Every knowledgeable user understands immediately as soon as they hold the tablet in their hands with or without a keyboard, that it is a quality construction, without anything creaking, moving, having any color difference point by point, or anything else.

SOUND.
And the sound is loud and clear, no matter how noisy the environment is, I can comfortably hear what the tablet is playing. Of course, I'm not referring to extreme cases, like working next to a compressor or being in a bar with loud music.

WEIGHT-SIZE.
And these are the strong points of this tablet, with a weight of just 768 grams and an ideal size for someone who wants a satisfying-comfortable, high-resolution screen without the problem of weight and transportation, especially for someone who moves on foot or by motorcycle like me.

WIRELESS CONNECTIONS.
It supports Bluetooth 4.1 technology, which means automatic reconnection with connected devices, as well as wireless management via LTE. It also supports connection with multiple devices simultaneously.
Of course, it also supports the dual protocol of wireless network WiFi 802.11ac.

SENSORS.
And as for sensors, it is, I would say, rich since it has ambient light sensors, an accelerometer, and a gyroscope.

OTHER FEATURES.
The solution that Microsoft provided for supporting the tablet with the adjustable setting in any position the user wants is flawless.
The same goes for the solution with the magnets used to connect the tablet to the keyboard and the charging port. They are so powerful!
As soon as you bring the tablet close to the keyboard, before you even realize it, an invisible force securely attaches the two parts.
The same applies to the charging cable, which, I must say, has no right or wrong position, it connects however you want and even has an indicator LED light.
In the end, it's true that you get what you give. I mainly bought it for its screen, but it is very good in all aspects and has changed my standards of expectations. I realize this when I rarely pick up my previous tablet anymore.

9-6-2018
Today I tried making a call through Viber for the first time and it impressed me, not so much because of the sound I heard (it was expected to be good), but because of the microphone. I asked my conversation partner how they could hear me and the answer was very good, just like with my Galaxy S8. I mention this because with previous tablets I had, whenever I made similar calls, I always received complaints about the sound.

3-10-2020 it still works perfectly, except for the battery life, which has decreased depending on usage to 4-5 hours.

21-09-2023
The battery now needs to be replaced, and this is a serious problem. Wherever I went to have it replaced, they told me it is very difficult and I have to take responsibility in case the screen breaks. At Microsoft, the cost of replacement is 550 euros!!!!

30-05-2024
I have changed the battery, and it left a small flaw, a shadow on the screen when it displays a solid color. However, the shadow disappears when viewing images or videos and does not create any problem. The cost of changing the good battery was 70 euros, plus labor costs of 40 euros, totaling 110 euros. I am very satisfied because I have had this tablet for over 6 years and it works perfectly.

The only downside is that it cannot upgrade to Windows 11.

For those who have (750+120)=870 euros and are considering getting a Laptop with tablet capabilities, this particular one is an EXTREMELY GOOD CHOICE.

I will start with the POSITIVES:
- Top-notch build quality.
- Absolute portability.
- A screen that you won't find anything similar to at this price range.
- The Microsoft keyboard (Type Cover) is EXCELLENT and backlit and functions as a cover.
- Completely silent due to the absence of a fan.
- Very good compatibility with the pen (+50 euros).
- Windows 10 (For those who use it for more than just social media, gaming, browsing).

I will also mention the negatives:
- It should be sold together with the type cover.

Finally, for those who want more tablet and less Laptop, I would not recommend it.

Ipad killer. Screen from another planet, battery that lasts the whole work day, flawless stylus and touch, and amazing build quality. I haven't tried games and I don't think the low specs of this particular device are intended for gamers.

From the moment the warranty period expired based on the receipt I bought it, it started to break down and drain money! There is no dealership in Greece and they told me to send it abroad and replace it with another recycled product. First, the magnetic keyboard broke and I bought another one (100 euros). Then, the magnetic charger broke and I bought another one (70 euros). Then, the front-facing camera broke and my Skype contacts couldn't see me. This was never fixed. And finally, before 3 years passed, it CRASHED for no reason (BIOS damage) and never recovered. The technician even told me that he couldn't recover my files because the laptop is compact and it all breaks together... Now I have to buy another one, but never again Microsoft, because I had exactly the same experience of rapid total destruction (and in just 18 months) with the Lumia smartphone.