If using as part of a 10.5 or less 5.56 pistol build how would you rate adding a superlative arms "bleed off" gas block?
Would you recommend this over buffer weights and spring rate fiddling?

If you own and have used one, would you make the same purchase again after installing it?

Don't buy one, if you have a problem and try to contact them they will completely ignore you.

Had one wasn't really impressed. It worked fine. Just wasn't for me.

I had one of their bleed off models. After two days at the range the adjustment screw broke while shooting, rendering it useless. Superlative ignored my emails and phone calls.

Bought an SLR, no issues since.

Wow! I was hoping to see some positive! ....and more response since they are sold out!

I have one on my GII (16" barreled Recon model).

The rifle works just fine with it.  So far, no broken/missing parts.

The only thing I noticed is that when I followed the adjustment procedure I turned the adjustment screw all the way out past the point where the locking mechanism would hold the screw in place - before it ever got to the point where the rifle stopped working for lack of gas pressure.   I mean, the instructions said that at some point, as you adjust the bleed off screw more and more open, you'll get to a point where the rifle will fail to function and then you have to turn the adjustment screw back in.  Mine never got to that point before the screw was out past where the detent would catch and hold the adjustment/venting screw in place.

I was planning to buy another one this winter, for a .223 AR15.

It's the only one I've ever owned, so I can't really compare to it to another brand/model.

I have 2 of the SA gas blocks, both on 6.8 AR builds. They've always worked fine for me, on ARP 20 and 16" barrels, with standard carbine springs and buffers. I did have to back out the screw a ways to get the "failure to lock back", but never so far that it came out. Lessened recoil a lot on both, nearly the same as my 5.56/.223 AR's [without adj. GB's]. I suspect many barrels have oversized gas ports to achieve reliable operation, and that could explain why some people can't bleed off enough gas to get "failure to lock back" before the screw reaches the end of it's travel - supposedly, there's a stop at that point to prevent it from coming out of the block, but if you crank hard on it at that point, you can probably get it to come out. IF I ran into that situation [gas port too large to effectively bleed off enough...], I'd try turning the screw clockwise to "restrict" the gas instead, which should also work about the same. I plan on getting more of these to use on new builds and to retrofit to some of my older AR's in 5.56 that I know are over gassed. I'm pretty impressed with the machine work on these - beautiful, fit is great, work well with suppressors, and they install easily.

I run one on a 300 Blackout, it replaced an old PRI AGB, not enough rounds thru it yet to give a meaningful review. However Todd Magee at Dead Air loves them, see this thread:
thread on adjustable carriers

Have both the SLR and the SA.  They seem equally nice, the SA is a bit better of a design though.  About 4000 rounds on both, neither seem phased.