Personal opinion, as it didn't suit me in the end and turned out to be worse for my wrist compared to the simple ones. But it depends on how it fits each person.

for its price it's good. its flaw is that it has a short cable and it has forced me to change the position of the tower. the left click becomes a problem over time, as I have noticed with all mice. I also noticed that the mouse remains on even when the computer is turned off

At first, it is difficult to get used to it compared to regular mice, but over time you get accustomed to it and it is absolutely ergonomic!

I have it at the office, I easily get tendonitis and my job requires me to be 8/8 with my hand on the mouse and it has been very convenient for me. Lightweight, convenient, fast with the side buttons just right. The first day until I got used to it felt strange, I have had it for 3 months, I am thinking of getting one for home too

I do not recommend it because it is not comfortable and convenient in my hand.
I have worked with another vertical one that was really comfortable, although much more expensive of course. (Having the right shape does not affect the manufacturing cost that much, which is why I make the comparison. In this one, the thumb is in the air!)
In terms of quality, nothing more than what you expect for its low price, especially the wheel has a completely cheap feel.

Affordable, lightweight, and with sufficient accuracy for daily use at work. I have been using it for 2 years with slight superficial wear on the rubberized areas where you hold it, without negatively affecting the user experience. If it breaks, I will buy it again.

I use the mouse every day in the office. Don't look for many details like noise, weight, response, etc. It works like a regular mouse. If it breaks again, I will buy the same one. Of course, you can go to another price category but believe me... there is no reason. It does everything and it's worth it.
And now let's go to the most important. I got it because I have a very serious carpal tunnel syndrome. For the four months that I have been using it, I really, really forgot that I have a problem in my hand. Get it to be saved!

I bought it because of its many positive reviews and its low price.
I have never used a vertical mouse before.
First impressions are positive. The hand is in a more natural position and gets less tired. As for the size, it fits me well (I have a normal to large hand).
The left click is excessively hard and strains the thumb. The right click and the scroll wheel are okay.
After contacting skroutz, I requested a replacement, which was done without returning the original!
The new one is nothing like the previous one in terms of the left click. It is very soft, pressed with normal pressure. This way, the thumb does not get tired. Everything else is okay.
The buttons make noise but nothing excessive.
We still have to see its durability.

Whole turkey
Waste of money
The left click is not functional as it should, meaning it requires force
The right one is okay

Good mouse for its price. The truth is that it helps to have the hand in the right position and prevents tendonitis, etc

After 4 months of daily use, my thumb started hurting. I was putting pressure on my thumb to maintain the balance of the mouse. Additionally, it was too big for my hand. It works better for larger or male hands.

The first one I got perfect. The second one, however, is very hard left click and that's why I will allow it. Obviously it has to do with the batch. I have tendonitis and beginning carpal tunnel syndrome. I have recommended it to everyone!! Huge difference in hand.

Obviously, it depends on the size of the wrist for each vertical mouse. For a male hand, it is ergonomic and relieves the wrist, it does not require a "pad" for raising the wrist. The positions of the thumb buttons "before" and "after" are located at the top and are convenient, the function on the other button higher sideways is indistinguishable in Windows10.

I bought it because I have tendonitis and I decided to try an ergonomic mouse. Maybe it's a little better for my hand, but it still hurts when I click too much. Also, yes, it's hard, but for 10 euros it's fine. And the size seemed fine to me.

I have it for 5 days now, it seems to no longer hurt my hand. For its price, it's fine. It lacks a bit of balance, as when I left-click many times, it leans to the left. Its wheel is okay, it is a wheel with a brake when you release the finger. The line with the blue LEDs would be better if it didn't exist.

10 euro mouse to save you from carpal tunnel syndrome and general hand pain. The best thing ever. I no longer have issues with my wrist. It takes a few hours of use to get used to the different hand position, but the brain adapts quickly. As for durability, I can't say yet. I assume the wheel will break soon. Expected from a 10 euro mouse. If you work on the computer, switch to this style of mouse quickly.

Now that I use it, I wonder how I worked with non-ergonomic mouses. Very convenient with good handling response. Highly recommended as an affordable and reliable accessory.

Very comfortable, convenient, and affordable. The most difficult part is transitioning from a regular mouse and adapting. For its price, it is very good. The buttons make noise, but it is subjective whether someone wants it or not, personally, it serves me well.

It is VERY comfortable. First time trying such a mouse. It responds excellently. I have already bought a second one. The price is also unbelievable.

The difference from a classic mouse in grip is immediately noticeable. It is very good for its price. My wrist stopped hurting from the first moment of using it

It is comfortable in the hand and made of nice material, but its size is a major disadvantage. You need to exert a specific force to press the keys, and the mouse easily moves from its position at that moment, resulting in clicking slightly off. It is good ergonomically, but otherwise I would not recommend it so easily

I have bought another Gembird product and I decided to try this one as well.
It is cheaper in terms of construction, but the main disadvantage is the click of the mouse. You have to apply some force to the finger to press the button, which I consider the main reason why I returned it.
Also, another thing that is not good (which the other Gembird mouse also has) is that it slips from the hand. These types of mice should be designed to "stick" to the hand (like basketballs, for example).
It is lighter than it should be (so much so that, combined with the difficult click, it forces you to click closer to where you are aiming!!) Overall, the hand is in a more comfortable position compared to other mice.
If it didn't have these two problems (difficult click + slippery surface), then I would highly recommend it

Even if you don't have a serious problem with hand pain from using regular mice (which many have bought in smaller sizes than they should have because they bought "laptop mice"), it would be good to try this type. Especially this model at the embarrassing price it is offered will completely change your mindset. I believe I will never buy a non-ergonomic mouse again. And I got this one as a test, so I didn't spend more money on it.
The only negative thing is that because I also play a game that requires precision, its response/accuracy may not be perfect. But still, I won't change it to play with the classic one out of fear that my hand will get caught again.

I have it for a week and it is very comfortable in the hand. Those who have issues with a regular mouse and use it for many hours every day will notice a big difference from the first day. It is worth its money.

Finally, the hand in the right position on the mouse! In the first 5 minutes that I used it, I understood the strain that regular mice cause. I got used to it immediately! It is user-friendly, lightweight, and its material is this "velvet matte". The only negative is that the buttons are a bit hard to press and make noise. Over time, it will show if this creates a problem. I have had it for 2 weeks.

I bought the product about 2-3 weeks ago. I use the mouse a lot in a design program, so I use it quite heavily. It took me a little time to get used to it because at first you hold it very tightly, but gradually you get used to it. I didn't have any issues with its weight. The buttons respond immediately and functionally it has no issues. Personally, I don't really like the feel of its material, but that is a matter of personal perception and not objective. Overall, it is a good product and I think it will ultimately be more comfortable than the traditional mouse (I just need a little more time to get used to it!)

A major disadvantage is the weight of the mouse, the cable tends to drag it from its position if it is slightly pulled. Fortunately, it has plenty of space inside, by opening it and sticking a couple of weights with insulation it becomes amazing. (Obviously, you get what you pay for, it is not comparable to mice three times its price, but for office work / non-demanding use, it is fine.)

Third day of operation, very positive impressions. 5 stars for the price/quality ratio.

UPDATE (2 stars) 04/01/2021: After approximately six months of use, the following problem appeared: the wheel has become loose (moves) quite a bit. During scroll down, it "skips" some steps and either does nothing or goes in the opposite direction upwards.