Just an update...
I ended up getting the Logitech G5 yesterday just to try it out. The idea of the laser was appealing as I use it in various locations and not having to worry about surfaces is very useful.
So, far it is working very well. I have to get used to the shape but it's not a big problem. I like the accuracy thus far. I did try it in some TF2 and Day of Defeat action and the rez switching is really useful. I can say that it is MUCH better to use overall than the Apple mouse. I also tried the weights and found it to be plenty weighty without them. So, that aspect appears to be lost on me. This may sound silly but, I really like the cord design - it seems to be a little more manageable than normal mouse cord coatings. My only wish is that they had it in plain old black or something besides the blue scale-texture.
BTW I did just plug it in and it worked straight away except for the thumb buttons. The side-scrolling works fine. I have not used it extensively yet for design work...that is later today
-mx
yea i did notice that my old mx500 side buttons did not work properly with the standard os x drivers but all my mice have worked fine in windows out of the box.