I use the G7 which is essentially the cordless version of the G5 (minus the weights). the precision (true laser), on the fly adjustments and the quality really sold me on it and I have yet to regret it. A friend of mine got the G5 and has had alot of fun with the weights, though I dont know how much I would find them useful. different strokes for different folks.
As far as mouse mad goes, I am using a generic pad. works for me. I have heard of some pads (even the high dollar, like the ICE) have issues with optical, so check the reviews for any issues on your pads.