I have a TechSights dual-flip aperture that I love, however, I decided that the Eotech with QD is probably all I'll ever need (and I'm getting better with irons). These have been taken on and off like 25 times––it took me 4 minutes the first time, but now I can get them off in 30 seconds and on in 35-40 seconds (usually!). It comes with a moveable guide rod, spring and retaining collar so that you can just put the whole thing in and switch it out with your regular recoil spring assembly without having to switch all the parts (an $18 value––total savings is over $47 shipped).
Will post pictures if someone really needs to see them––though you can always go to their website...mine look like those.
Email and pp is JFLOW25@GMAIL.COM