HEXiT :
g600 has a major fault in that it skips badly due to poor firmware.
not a good choice.
mmo mice are a gimmick at best , much better to get a basic or near basic gaming mouse that has a good reliable tracker and simple controls.
anker precision laser gaming mouse uses the same 8200 dpi as in the g600 but doesnt skip, it has 3 thumb buttons and a total of 9 buttons in all 7 of which are programmable with 3 different pofiles each.
there are many other mice as good as this 1 but non at its price point of £30/$30.
if you want something thats distinguished from the pack then look ar roccat or thermaltake. corsair also have some quality mice.
I haven't had the issue with the G600 mouse skipping. I did see people mentioning that when it first came out. Perhaps they solved that problem.
I'm not sure why you think MMO mice are a gimmick? Once you get used to the functionality and the buttons you've customized, it's pretty convenient. The arrangement and angle of the buttons makes it pretty easy for your thumb to 'recognize' where each button lies. I'm sure some people don't have the patience for programming the buttons and acclimating themselves to the custom controls, but once you do, it's pretty convenient. I haven't even ventured into using the ring-finger shift key to assign another set of controls within a profile, but it's there when you need it.
A huge consideration with an MMO mouse and someone who is into MMOs is this is a game they will be playing day in and day out. The functionality of the G-buttons can be phased in as you discover new ideas for macros or as you find ways to make key presses more convenient by assigning them to the G-buttons. As a result, it becomes that much more useful to MMO players. I think this is where the increased value is with the MMO mouse.
Bystander told me about the g-key on the G600 thing in another thread, but I must not grip the mouse as tightly as I haven't had this issue with inadvertently hitting the G-key. It is something to note though. I hadn't thought of that before I picked mine up. I went to the local store to see how it felt to make sure it wasn't an issue.
It's really all a matter of preference. The G500 is a good option with fewer buttons. I used this for around a year and a half. Really, I was fine with the G500, but really curious about the G600 and the possibilities. So at this time, I'm committing to the G600, but have found no real issues.
Additionaly, there's a Logitech G9x that's a heck of a deal on Amazon if you can look past all of the COD labels:
http://www.amazon.com/Logitech-Gaming-Mouse-Call-Duty/dp/B005S0KHIC/ref=sr_1_1?ie=UTF8&qid=1362491639&sr=8-1&keywords=logitech+call+of+duty+mouse
The cheapest I've seen the non-COD version of this mouse is $65. It's good for FPSs, especially.
Personally, I won't use anything wireless when it comes to mice because I've had batteries begin to go on me in the middle of a click/drag file operation and the results are not predictable. I imagine it would piss me off in the middle of a good round of BF3 as well.