I’ve been using trackballs for over 20 years and much prefer them to mice for work (I do use a mouse for gaming though). After my MS Trackball explorer died, I went through a few others, and currently use an Elecom Huge as my main trackball, which is quite good.
This looks a lot like a clone of the MS trackball explorer, though, which I LOVED….I may need to pick one up.
So I picked one up on your recommendation. Using it on Windows. A little bummed it isn’t natively reprogrammable, but comfort wise it is essentially identical to my old MS explorer. The soft touch finish is a bit slippery out of the box, so my hand has a tendency to slide down after a few seconds. We’ll see how that works long term. I am finding the wireless connectivity to work pretty well.