Works perfect. Took me some getting used to but overall great buy

This is the 2nd one I've bought. The 1st one lasted 7 yrs which having been used almost every day speaks volumns. The only reason i bought another one is that somewhere between Williston NDakota and Houston.. the dongle decided to take its own vacation.

Love it! Lightweight and comfortable to use. I don’t like that it requires batteries and can’t be recharged, but the battery life is impressive, it doesn’t drain them quickly. I’ve had it for about 1.5 months and haven’t had to replace the batteries yet. I mainly use it for gaming, and the extra buttons are very helpful. The wireless connection is perfect and never causes any issues.

One week in to using this mouse, so just preliminary comments.
Firstly, I found it surprisingly easy to adapt my hand to using this vertical mouse, unlike some other reviewers who feel it'll take time.
So far, I haven't noticed a huge difference in wrist/arm pain, but it's early days and my symptoms are not all associated with CT.
The mouse is very comfortable to hold, but, like some others, it may be a little large for my hand, which measure 7" from wrist crease to tip of middle finger, and 3" across the palm at the base of my fingers. My hand tends to slip down so the index finger rests on the wheel and my little finger rests on the desk surface. The surface of the mouse is very smooth, so I may try fixing that with some non-slip stuff.
Connection to my PC was very easy, just inserted the supplied dongle into a USB port and off I went.
Motion is smooth. Sometimes, left clicking requires a more positive press to register on the screen, maybe because my finger isn't positioned properly. Double-clicking also can miss, and I think until I fix the 'slippage' issue, I may have to adjust the click rate in the PC's settings.
I recommend using a wrist support with the mouse as it helps to raise one's hand up a little.
Sound level is quiet - good as my office is connected to the bedroom.
So currently, the major con is the overly smooth surface.

It connects very easily, either via Bluetooth or USB, and works perfectly on my laptop and desktop. It feels light yet sturdy, the quality is very good, and the vertical grip has relieved my wrist discomfort. The buttons are quiet, and I can adjust the speed to my liking. It's truly changed the way I work.