Cougar 600M is a fairly standard gaming mouse. Sure, the shape is slightly unorthodox, and it's clear someone worked into mixing ergonomics with flashy design. At its heart, there's an ADNS 9800SE laser sensor, which looks impressive on paper, but unfortunately, its known faults have not been repaired here. I have discussed about this sensor a lot when I looked at GX1000, Corsair M95, Corsair M65 gaming mice. I will not go over its slight negative acceleration and latency issues again. All you need to know is that they're there, but they're not noticeable unless you are a low-sensitivity player.
Except that, how does it fell in the hand?
I am a large-handed palm-grip user, and for me, it has a surprisingly good feel in the hand. All buttons are easily accessible, and the 45-degree angled Trigger button is surprisingly easy to press. Overall, it's a good enough palm-grip rodent even if it lacks many of the proper aspects that make it right a palm-grip. However, for one such as me, the small-shape was not a great thing, but that was to be expected.
However, Cougar intended it for palm-grip users who like their mice small and light, which is why I am even more baffled by the sensor choice. The individual left & right click buttons means you can press from the back and get pretty much a similar feedback as pressing from the front. The mouse weighs only 90g so that means you can use it with ease on massive pads, and the Trigger Button is large enough to be pressed from the back with ease.
If I would have any complaint in this department that would be that Back & Forward as well as DPI Up & DPI Down for some reason are really tough to press and they do not have the same clicky feel like left & right click has.
This is always is the crux of the matter. If 600M would have used a 0-ish tracking issue sensor like the PMW3310DH, ADNS-S3988 then this would have been a fantastic low-senstivity claw-grip mouse for FPS players (since there are not many of these). However, with ADNS 9800SE being used instead, I simply cannot recommend to someone who uses less than 600DPI when playing.
However, if you are someone who plays MOBAs and MMOs, and you end up using macros from time to time, then know that the Cougar UIX is one of the most extensive and easy to customize macro-creation packages out there. While I am not one to create overly complicated scripts that pretend to be macros, I can see how UIX's iteration is by far one of the most effective I've seen in gaming mice.