i also own the G9X.. i have 2 friends who use RAT 7 and RAT 5... i still don't know what they like about the mouse.. for me, the G9X is much simpler that the RATs, though i hate the profile change button on the G9X..

but i have to admit that the RAT looks extremely cool!!especially their new albino mouse..

they look the same, but several features are not available on every rat... for example, you can change the weight on rat 7, but you can't on rat 5..or rat 9 is a wireless mouse, but rat 7 is a wired mouse....

I've used the X3 before (a used one) and I have to say that I'm very impressed with the mouse. But I don't like the button on the side of the mouse, sometimes it's very hard to reach, especially on the other side (the mouse has a button on each side), and the units that I'd received was quite hard to press (the macro button).

I have a big hands and the mouse fit perfectly...It'll be a good mouse if you can find a cheap one..I'm not sure about the warranty, but my friends did swap his X8 with a new one (he bought a used X8)..