So far loving the Ergo (w/ trackball). Much better wrist position than Vert (that hurt my wrist).

Wish you had another thumb button(s) to the left of the track ball. or even two (fwd/back). You can totally fit them. Rn fwd/back are moved to index finger - awkward. Maybe takes getting used to?

Also, why don't you have an awesome scroll wheel like on MX Master? I want a rolly wheel w/o stops. If this mouse had this feature it would be an absolute winner. Rn i'm not sure which to pick, ergo or mx master. Yet to try MX master. But def returning Vert.