For those who spend several hours on the PC due to work, it is just what they need to prevent tendonitis... It does its job and more, it just takes some getting used to the transition from a horizontal mouse

A first look (and probably the last).
Purchased on 6/12/2019 at a price of €9.50, prompted by discussions and evaluations regarding its practicality. I have no experience with this specific function, so I judge based on what I had. Its use: for many hours of computer work.
I used it for a few days (about 15 days) and then I didn't use it again, and there are two reasons:
1. Its clicking was often inaccurate, resulting in extreme fatigue during use (perhaps due to its mode of operation). It constantly moved any background and did not click immediately where I wanted it to in the operating system (Windows), even though I tried various settings through the operating system. Its performance was much better in games.
2. (Unrelated to the mouse, related to its mode of operation). After a considerable amount of time using it, I felt discomfort in the base of my palm and towards the outer side, where the hand rests. At first, I thought it might be the beginning and that I needed to get used to it. However, as time passed or as I used it for several hours, I had the same discomfort and even reached the point where I didn't know what was worse: this or carpal tunnel syndrome. I decided that this was worse.
Since I have no intention of using it again, what I have to recommend is, before purchasing an expensive model, regardless of whether the mouse is good or bad, buy a cheap one to see if it suits your hand. You might save more money.

The keys are not silent, as a construction it has a nice design but it is a bit difficult to press the keys for my hand (I should have had a bigger hand :P) but overall it's so-so

Excellent tool, for the past two years it has been my constant companion with several hours of daily use without any discomfort in my hand. I have also purchased a second backup in case anything happens to it. I highly recommend it.

After a year of use, it saved me from hand pain. Of course, it takes about a week to get used to it.

Very good mouse for people who work many hours with a computer and/or have some form of tendonitis. In mine, after 1.5 years, the wheel gave up (specifically the scroll, because the click still works) and I immediately ordered the same one. However, I also used it for gaming a lot, so I believe it would last longer with normal use.

For its price, it is definitely worth it!