In short, fantastic.
Assuming you don't have the G700 to compare with, it has a very ergonomic shape similar to the old Logitech MX Revolution. The extra buttons are easy to reach.
The top hydrophobic surface is smooth to the touch, yet not slippery so no need to worry about fingerprints. The sides are a textured plastic for a good grip - way better and longer lasting than the sprayed-on rubberized crap we're used to.
Wireless works well and battery (Eneloop!) life depends on the polling settings you use.
Only problem? No bling-bling other than the side LED indicator for battery-life/DPI settings.