I bought a Logitech (G500) gaming mouse this evening, I absolutely love it but there was one huge problem.
When I moved the mouse in the game, the game lagged like MAD and my CPU resources went from 5% or so to almost 70%. Lag was so bad while moving my mouse that the little balls on the putting grid would completely stop.
After hours of Google searches, I found the problem.
Most mice have a polling rate of about 125, the Logitech Setpoint software is set to make the default polling rate 500. This in turn eats a ton of USB power and a ton of CPU resources.
Simply go into you your setpoint settings, click pointers and go all the way to the bottom. Set the polling rate to be 250 or less, or whatever "feels" right in the game.
Problem solved!
Anyone with a gaming mouse experiencing severe lag should check this setting ASAP. It didn't really occur while using other applications but definitely killed the game for me.
WGT - You may consider stickying this post for future reference. It could be a huge lag issue for many users.
Good shooting!
GD