One minor nit with the M325: They've moved the optical sensor on the underside of the mouse from the right side of the mouse to the left. This might seem like a completely trivial difference, but it is actually taking a little getting used to. Without even being aware of it, over the past couple of years I had apparently conditioned myself to make small vertical mouse movements using just the ring finger of my right hand (without moving my entire hand). This was great as long as the sensor was on the right side of the mouse. With the sensor on the left, this no longer works; the cursor moves in more of an E-NE/W-SW direction instead of nearly straight up/down.
I suppose lefties might appreciate the change though...
The years just pass like trains. I wave, but they don't slow down.
-- Steven Wilson