When I think QD, only one name comes to mind: Larue. I've had nothing but luck from everything I've bought from them, and their customer service is bar none.
Used LaRue mounts on several of the weapons. Never had a failure to date.
There are many excellent tactical mounts available to choose but I highly recommend those made by the guys at LaRue.
Check out Warne scope mounts. I'm getting ready to pull the trigger on one. I believe Jesse Tischauser here on the forum is sponsored by them or runs them.