KDG SIDELOK is a great option in my opinion. Return to zero capability, not nuts or bolts protruding out, clean design, customizable in moving the rings on the platform, rock solid lock up. Its a very interesting system, that hasn't let me down in the past year that I've owned it. I take my optics off pretty periodically to utilize my night time optics and it always returns to zero for me.
Well i guess technically they arent, they are all just unimounts. with the two bolts system. i wasnt paying attention to the original question about QD's. I always recommend badger. i have had nothing but success rifle after rifle with them. Guess that makes me a fanboy.
Then I think you'd definitely like the ARC M10 QD-L, they are finely machined, solid build, unique one bolt torque with minimal scope twist. I use ARC rings whenever possible, there are lots of great rings and mounts out there, but the unique one bolt torque design of ARC is what sets them apart.