anyone try a set?  if someone has some nice photo.. that would be cool. from what i can tell. the seem to be pretty slick and low profile..

i am thinking of picking up a set from primary arms..$140 sounds pretty good for the set...

I have two sets of the QDS sights and I love them and plan on getting more. They are pretty low profile. I'd jump on that price.

I have several sets.  They lock up and down which I really like but the two aperture model is not exactly low profile.  They use a rear aperture like the A2 where the two apertures are at 90 degrees to each other, so when folded, while the body is very low, lower than TROY, the small aperture (large aperture is default) sticks way the hell up there and scopes in rings that clear a TROY easily do not clear the YHM QDS.  I really like them and have an equal amount of YHM QDS and TROYs, but if a scope is to be used over them then I use the TROY.  
My ideal sight would be the TROY that locks up and down or the QDS with the angled apertures that are lower profile.  I have had problems with TROY sights walking up on recoil from the .500 P and .470 Rhino and even the .458 SOCOM with 500 gr. bullets although they do not walk up on the lesser recoiling rounds like the .458 S 300 gr. and 6.8 on down.

I have the QDS rear sight on my AR10 with a bushnell elite 3200 3-10x40 short action in a burris pepr mount.  The second aperture sticks up so much that I can not move the scope back far enough for my liking.  If you are using red dots or scope with long eye relief or extra tall rings they would be fine.  I am going to get a troy rear sight for the ar10 and move the QDS to my DTI M4gery. The sight is built tough and I like it alot but it is not suited to be used completely under the eye bell of a traditional high power optic.

oh that bites!