I know this topic is old but for all the people still reading this:
The choices of the mice that the topic starter had are bad.
Mamba is a big fat heavy mouse, it is good for a low sensitivity user with a big mousemat and enough space, but when it comes to fast actions etc. its bad.
The second microsoft mouse is a general desktop mouse, good for a casual gamer that doesnt care about hardware.
When it comes to fps games, precision and long time use id pick from the following mice.
Logitech:
g5 or g500(g500 has weights and more options)
MX518 ( PERFECT mouse for palm users, very lightweight recommended for snipers)
G9, personally never used it, but for the gamer that also does some MMORPG's its really nice.
Razer:
Copperhead (a really old school mouse, VERY lightweight nice layout. Long time use gets u crampy hands).
DeathAdder ( PERFECT mouse, good for right hand users, they put a lefty on the market too. its very lightweight, cool effects. anti slip, good for people with sweaty hands.)
DiamondBack (well what can i say about this one, its almost the same as deathadder, more Hz and DPI settings, a little bigger, just a LITTLE.)
Microsoft:
This is a easy topic, either choose from:
Intelli explorer 1.1a or 3.0. (they do have a scroll bug but its easy fixed, TUTS on youtube)
BOTH lightweight good for palm users.
Roccat:
All mouses that they brought out are good, they have many options.
Steelseries:
HAH! yes ok, most inexpierenced gamers would pick the most expensive ones here. but i'd say, when it comes to steelseries GO LOW.
Kinzu (good mouse, a bit light and small)
Xai (same as Kinzu, but has internal storage, good for LAN gamers , but double check it. it bugs)
Ikari ( Personally for me this was a waste when i bought it, i HATED it. its smaller than the Xai and Kinzu, and more bulky. It does have more options.) (if you decide to go with the optical, its a good mouse for snipers, still bulky)
I havent tried more mouses than these.
Hopefully I helped some FPS gamers pick a mouse.