I have the :
1. G Pro Wireless/GPW
2. G305
3. G703
The best is subjective to what you play, but you can get used to any of these mouses and play really well with them, best ergo is G703, best budget G305, use the weight reduction trick with the AAA battery, bring the weight down to almost GPW levels, and last up to 2 weeks run time, the shape might take a week or so to get used to,can be had for £20+ in certain sales, The GPW quite expensive can be had for £100 maybe less, good light weight, very good battery life last for a 1/2 weeks charges quick, doesn't immediately feel good, takes a few weeks to get used, just have to stick with it, will initially feel like you wasted money, but its my main ATM, bit to expensive thou, the new king is apparently the new Razer Viper Elite, as good/better then the GPW little bit lighter, well balanced feels similar to the gpw..etc! but real expensive! at £150