What would you think of the security (not convenience) of QRs that install with an hex wrench? I've seen some very light-weight (30g-40g) QRs that install this way.
the 30-40g ones are titanium, and you have to be really careful with them. They tend to bind up a bit, and you can shear the heads off of them if not careful. There's a very fine line between tight enough, and too tight. I ended up snapping the head off one of mine trying to unscrew it, and stripping the hex bolt out of the other one in a hurry. Not the sort of reliability I was looking for in a skewer
So now I run ~70g steel ones, and am pretty happy with them (halo - they were ~$20). Great clamping force. And since I carry a 5mm hex wrench with me all the time anyways, not a huge deal. Granted flat repairs take a little bit longer, but I'm willing to make that sacrifice.