Okay, I've spent the last 2 days using this trackball and I must say that's it's really nice. I left hand the trackball and I'm used to left clicking with my index finger and right clicking with my thumb. The ball is super smooth and the scroll function up top is fast. Money well spent here. I'll have to pick up a couple more down the road.
I do think I like this unit better than the DT 225 if not for just the scroll. But I could happily live with either.
skc