The Expert Mouse costs a lot, lot more than a simple trackball. And my subjective feeling is that it's actually less ergonomic than the cheaper Logitech I've got.
I cannot use that kind of trackball. It relies on actuation with my thumbs, and it hasn't worked out very well in the ones I tried. I prefer "ambidextrous" ones with the ball in the middle.
There’s also the slightly smaller Deft Pro (https://switchandclick.com/elecom-deft-pro-review/) which I also own and use for travel — it has a superior scroll wheel and therefore may be a superior choice for you.
For me the Huge has a perfect form factor that outweighs all else.
