Hi:
I did have to play with the trackball adjustment to my liking, but I have not noticed a lag. No problems at all yet with hanging up with the End Call button. It's one of my favorite things to do.
Ringer volume could certainly be better, but I have found differences in different ringers and my CTU24 ring seems to be fine. Of course I never get that far from my 8830...
SteveTaz