portaxeplayer wroteI was in the same spot a couple of weeks ago.
I ended up going for the G900 mainly because of its vastly superior wireless performance compared to the Mamba. In hand it feels very light and the tracking accuracy is absolutely wonderful in wireless mode in an environment full of interference.
In addition the software of the G900 is the best out there (not perfect though) but far better than Razer's.
If wireless quality is the most important thing the G900 is the only way to go.
Interesting :) ,Mate from where did you get it and what is the total amount you paid for. G502 Proteus Spectrum RGB & Logitech G602 are the two options available here. Guess I need to order from outside it is for ~ USD 150 in the USA - Special Order to here will make it around 250 USD with VAT. There is also the new ASUS ROG Spatha Wired/Wireless mouse but the G900 is even better.