I guess I'm in the minority here in liking Razer mice (even though they've had some bad ones too). I do use Logitech mice at work and sometimes in my gaming rig. I'm a big time mouse addict (still looking for that perfect mouse), and I probably own a dozen mice at this point. If I were to characterize my mouse preferences, it's mid to high-sensitivity, high accuracy , low input lag, minimum resistance, low weight, minimum lift (i.e I don't do a lot of lift and reset mouse position during gaming, and never during desktop use.) Some of the best logitech mice in the past (MX Revolution in particular) would not go over 125hz polling, which made them useless to me in practice, no matter how much I liked the ergonomics, buttons, features, etc. I also hate shiny hard plastics on the main two buttons, and less than stellar left click responsiveness - the rubber like material on the DeathAdder and its button response are very compelling features.
I use my DeathAdder the most, currently. Running at 1000hz polling with no acceleration. I also love the ability to control the backlighting, as I dislike gaudy lights on electronics, as a rule.
I don't like the G9 much in practice although it seemed perfect on paper - it's almost never been used. The G5 gets secondary use on my gaming PC and I use MX 518 at work. Haven't bought a new mouse in a while, but I'm considering the Razer Mamba - a wireless mouse with 1000hz polling sounds crazy and an improvement on DeathAdder ergonomics sounds nice too - price is unreasonably high though.