Which mousemat do you use?
I have the G502 and use a QPAD HeatoN Pro XL Gaming Hardtop Plastic Mouse Pad. I find that this is better for the G502 whose feet can catch on cloth mats. I also find that tracking and gliding is smoother with hardened mouse mats. I might buy the G440 mouse mat just so that it matches with my mouse but then again I'm in no rush.