The incredibly smooth and speedy feel of the trackball is the first thing I noticed when I got my 8900. It really is amazing... So hard to find words to describe it, except it's almost like it's floating on air. It's awesome!
I love the black too, and it doesnt show any dirt, but it's already starting to stick and i've only had my phone for two weeks! I dont think there's anything inside; it's so new!
I do like the 8900 trackball...I am just worried about crap getting stuck in there...I don't want to risk hurting my 8900 by taking it out and cleaning it! *worries*