For comparison I have no tracking issues with my RAT7 and use it on a Razer Destructor mat perfectly which is a very dark finely textured grey (almost black)
Strange. I had the same mousemat with the 9.
It always took about 8 seconds to wake up from changing battery on that mousemat (on a white piece of paper was instant. 8-10 seconds is a long time to not aim in game!). By tracking issues, i mean that now and again the vertical or horizontal axis would stop working for a few seconds (in desktop and gaming) and it can be a pain in the ass. Happened a lot on my black destructor - but it very rarely happens now however since I've changed to the white version of it. It's a comfortable mouse when you find the setting you like. I feel it's more of a Claw-grip mouse. What I like about it over the X8 (and im guessing the mamba too) is that it is quite.... airy. As in lots of gaps. Means my hand never sweats, which was a big issue for me with the X8.
Saying all that, I'd love to get a mamba and compare. Specially with it's new tracking system.
I've had no battery issues with the RAT 9, but it is fairly short so expect to change it once every day, and on the odd occasion twice. A big reason i chose the RAT 9 was cause it was always wireless, compared to the mamba and x8 which becomes wired when charging.
Though that's less of an issue for me these days, so if it doesn't bother you then it would be fine.
Still can't say for sure which one I'd recommend sorry. You'll have to decide what sort of mouse your looking for.
EDIT: Aaaaah i just remember the worst issue with the RAT 9. Every time I lifted it and and placed it back down, there was like half a second lag of the tracking kicking back in. Was so terribly annoying in FPS, particularly as I lift my hand up a lot. This was a deal-breaker at the time, until I got the white mouse mat and the issue went away. Hmm, maybe go with the mamba tbh.