I put a McCormick single-stage curved trigger in my M4gery and love it. For fast competition shooting (3-gun, etc... not long range precision), the McC S-S would be hard to beat...
As for 'defensive" purposes needing a heavier trigger (stock), I don't completely agree. I don't see myself EVER, as a civilian on US soil, Zombies or not, running through the forests with my AR, loaded down with full tactical vest, web gear and the like, fighting a guerilla war... Nor do I see myself doing anything like what our troops in A-stan and Iraq are doing right now. It just ain't likely. If it were, a heavy and gritty stock trigger would be a huge ASSET against mis-fires/impacts and I would put mine back in...
More realistically, I see an M4gery being used for house clearing duty or property patrol. Both of which would be in SAFE position until ready to fire. Once that decision TO USE LETHAL FORCE has been made and I put my finger into the guard area, I prefer the glass-like S-S my McC offers me...
Although a more remote possibility but imaginable would be a M4gery or A2 on a good single or 3-pt sling ready for quick access and me in DISCRETE MODE with a "go-bag" of mags (or tactical vest under coat) and other "gear based on need and threat" leaving an area affected by a radiological, biological or chemical terrorist attack... (I live 120 miles from DC so not too impossible) The last thing I would want is to draw attention to myself from nervous, edgy law enforcement or NG soldiers by looking like RAMBO as I leave to somewhere safer. For this sceanrio as well, I would want my McC S-S trigger...
YMMV, but that is how I see my TOOLS being used. The precision trigger is desirable for my intended JOBS...
Most likely, my M4gery and A2 will only see duty at the range... McC again.
Rmpl