Just a few issues here.

The Logitech Control Center wouldn't work to program the wheel button to activate Expose/Spaces. Research on the net suggests it is 32/64 bit issue. They recently released an update but it will not install on 10.6. In order to install Logitech's latest mouse/keyboard control center (v3) I had to view the app contents and specifically select the .mpkg to do the install. Even then, no Expose/Spaces support, but it does launch from preferences without any issues.
I always assign my middle mouse button to show Expose, All Windows. In order to make it work I had to assign Expose/Spaces to my F5 key, tell the Keyboard to use F keys instead of special functions, then assign the middle mouse button to F9 (if Expose/Spaces is set to F9 you can't do the assignment in Logitech because it launches Expose), then change keyboard back to use special assignments, then change Expose/Spaces to use F9 for showing All Windows.

In order to use my Safari plugins including AdBlock and Glims I had to change it to 32 bit.

And I didn't change my kernel to boot in 64 bit just yet, stayed with the default of 32 bit. The change isn't complicated, involves a plist change or manually holding down the 6 and 4 key while booting to activate 64 bit. There is a program that will make the
plist change for you on CNet.
No other issue yet.