Just an update.
Finally configured SteerMouse and the G500 works beautifully under ML. If anyone needs the preferences for my settings, let me know.
I have set the poling rate to 333 under Windows and saved it to the onboard memory.
Probably one of the best/most accurate mice I've ever used. The grip texture and the ugly colors on the top I could live without, but a small price to pay for a great laser mouse.
Why the hell can't Logitech just release proper drivers???
Let me revive this topic since i consider buying the G500.
they have a "gaming software for mac" on their downloads. http://www.logitech.com/en-us/support/gaming-mouse-g500?section=downloads&bit=&osid=32
aren't these the drivers?