I found the previous version of the Logitech Control Center unuseable: feature poor and buggy. In particular, the absence of per application settings was an unacceptable (ridiculous!) limitation for driving an expensive mouse (MX2000). All those buttons, and I can't define what they should do in Safari versus UT2K4? Good grief.

The new version has per application prefs, and so far seems more reliable. In fact, it fixed a nasty problem I was having with stuttering movement trying to drive the mouse with USB Overdrive X.

Yet I am quite sure that all the other complaints here are honest. I think I just lucked out. My experience with Logitech has generally been poor, and I have no intention of ever buying a Logitech mouse again. While the MX2000 is generally a good mouse, there are blatant problems -- like an incredibly loose power plug connection -- that really make me shake my head and think what a chump I am for still believing that "you get what you pay for." Ha!