My Logitech performance MX mouse has been working flawlessly with Lion and previously with SL
if you're talking about how smoothly you can scroll through websites with the wheel, you just need to install the driver from Logitech.
I use a VX Nano and scrolling through websites sucked until I installed the drivers and configured it the way I like. perfectly smooth now.
I'm not talking about scrolling but the way the cursor moves and how precise it is.