I just noticed that my QD sockets in my ALG EMR M-lok rail are NOT rotation limited (but videos of it say they are). Has anyone else noticed this? There is some resistance, but they WILL spin freely.
Personally, I LOVE the EMR M-Lock with a few quirks. 1) the "co witness" accessory rail does not sit forward enough (using the 13" rail, BARELY clears a middy gas block. Forget about using a 12" with a middy). 2) would like a QD socket at the FRONT of the handguard, not just the rear. 3) the exposed "button head" screws are kind of cheesy. Would like to see counter sunk flat heads.
For $115 (13") + $20 (accessory "co witness rail) = $135. Not a fabulous rail for that price, but not bad either (puts it in line with UTG PRO line).
It works, it's cheap, it's not awesome, but it's functional. That's my .02

Not surprised on the lack of the limited rotation on the sling mount.  The rail would probably need to be 2x as thick to make that happen.  Same thing for the countersunk screws.  for an 8-32 screw it would need to be pushing 1/8" thick in the wall to get it to sit flush.  Even more for a 10-32 screw.  Can't always have your cake and eat it too.  Overall I like these rails and will probably get one for a build at some point.  They make good stuff and I think they did a great job with this rail in balancing the cost vs benefit with it.

My qd's will rotate IF I force them. But there is enough resistance that is doesnt spin when the rifle is slung.

I don't know about those complaints given the price point.  I'm pretty damn happy with mine:

Are those zip ties holding on your vfg?

 

Yes, they are for the tape switch.  I wanted to run it like that for a while first, before committing to actually taping the tape switch to the rail.

I just got my 12" M Loc EMR and the QD mounts ARE limited.