Hope you didn't pay £108 for it ? As the 750W RMx is cheaper and better.
Ah right. I was going to suggest sending it back otherwise and getting the Corsair RMx 750W for £85, but if you are already sorted then good
It'll be fine. I'm using a 550W SuperFlower.
The Corsair is a better unit (Fully modular and a longer warranty as well) so I guess it depends on what you paid for the GQ and whether you want the hassle of sending it back or cancelling it etc.
No harm keeping the GQ though as it gets a good enough review from Jonnyguru website.
http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=454