I found this interesting as I use a trackball and pretty much always have. Right now I have an Logitech MX Ergo on my desk at home and work. For things like OmniGraffle I also have an Apple Track Pad for zooming in and out, etc. I just find the trackball better for 99% of my daily use. I also use a Filco Majestouch for the keyboard with Red Cherry switches. CMD-Shift for spotlight and everything seems to flow. I do miss the 3 button mouse, that needed a reflective mouse pad and my Type-5 Sun keyboard sometimes however.
I figure I can shepherd my collection of Logitech Trackman wired wheeled trackballs until I find something else with the correct feel. I love just using my thumb as normal mice do cause pain.
I have 2 left ... six dead over the years.
It just kills me the wireless version isn't as good.