I've had a Microsoft Trackball Explorer v1.0 since it was first introduced in late 2000 - early 2001 and like many found it to be superb for a non-gamer. Few years back the bearings finally showed wear and the overall function was not anywhere close to the original crispness. I retired it and moved through a number of other devices (Logitech Marble Mouse, Logitech M570, 7 button multiple DPI gaming mouse, etc.). As an aside I much much prefer a finger trackball to a thumb style. I knew of some repair services but never explored them further. Recently I got the bug to see if I could get mine up and running again because of some hand ailments that I'd developed. The most well known repairman operates on ebay. Cost is close to $60 for the full "spa" treatment plus shipping both ways. Not cheap for a device that originally retailed around $49 but in the years following Microsoft's discontinuance and refusal to allow anyone else to resurrect it in the marketplace, prices for rare NIB samples rose above $600 with used pieces less depending on condition.

Anyhow I said WTF and engaged the man's services. Got to tell you the damn thing runs like butter and using it again reminds me why I was so fond of it. No, the exterior still shows wear where the thin finish has worn off. He doesn't address this nor recommend same as it can contribute to switch function issues. No biggie... call it wabi.

I never got into the track balls. but I have a 12-13 year old Logitech MX Laser mouse. I love the weight of it and its accuracy. I have replaced the battery in it twice

I am also a Mechanical keyboard nut and recently started using my Old IBM model M. again.