Microsoft Trackball Optical

In saying all that, I give the Trackball optical an eight and a half out of ten, and the Explorer I give a seven out of ten.

It feels about as good on my palm as my Microsoft Trackball Optical. Assembly was "easy", and I appreciated the PCB's flexibility.

You probably have a lot more finger ball options at your disposal, but I *adore* the Microsoft Trackball Optical (thumb ball). I sent mine in to be repaired though (for like $100 USD) and the person absolutely ruined it, taking away all clickiness in the LC / RC buttons. I have not yet saved up to get it fixed by someone else, BUT — in its glory days, it was the best thumb ball that ever existed, speaking as someone that has owned every Logitech thumb-ball (afaik) and *almost* every Elecom thumb-ball that has existed.

I use a Microsoft Trackball Optical ball, it's lighter than the GameBall balls. Additionally these work and are a good deal: https://www.amazon.com/gp/product/B07NM3ZGXR - They are a similar weight to the MTO ball, but not as smooth.