"a big drawback is having the muzzle blast closer to the ear with a shoulder stock as opposed to holding the pistol at arm's length; the noise that reaches the eardrum increases exponentially: half the distance between the ear and muzzle = 4 x the noise not twice."
As opposed to what, exactly? A short barrel AR? You're not seriously comparing a pistol that can be carried on the hip with a full length barrel, full stocked rifle are you? Obviously short barrels and small guns are louder, but that's because their entire purpose is to be small; kind of unavoidable. Especially when the alternative is
no gun.
There's a reason
all, check-em,
all PDW's and full auto machine pistols have stocks. They are simply easier to use. And the same increase of control that makes an ultralight full auto the least bit usable also drastically improves the handling of a semi-auto at range and rapid fire.
I think the holster-as-stock concept is fatally flawed, since holsters tend to be firmly attached to their wearers. A telescoping/folding skeletal stock is much handier, and at pistol recoil, all that's needed (see VZ61 Skorpion, or a much-lightened Uzi stock). Doesn't need to be more than 6" long if you use a red dot, too. And the whole thing will still fit/lock into a thigh holster.
The biggest problem is probably getting hit in the face with brass at close range (lots of designs do this intermittently), or somehow getting a kiss from the slide when you crouch up on it too closely
"Some few people might shoot this much better than a handgun. But with a decent level of handgun proficiency, most folks will not gain much if any accuracy with this kind of setup, unless you are adding a full forestock, extra muzzle mass, and proper sights."
Sorry, I'm calling BS. AR pistols are
far less usable than stocked (or braced) versions, and it has nothing to do with their weight. The same goes for lighter/smaller guns, too. The Steyr TMP was even too unwieldy in all of its four or so pounds, so Brugger & Thommet added a stock when they bought the rights. This ain't the movies, where the John Woo gunman can make hits beyond 100yards with precision if he trains hard in a montage and wants it bad enough. Sight radius on handguns is small, and an extended hand(s) is not stable, so accuracy suffers rapidly. Stabilize one end of that sight radius on your shoulder, and it effectively grows to the length from your shoulder to the front sight.
The NFA's got us so turned around we don't know what's good anymore (heck, just the other day I met a Brit transplant learning to shoot an AR at the range, who claimed that some rule of theirs that a rifle's trigger must exceed the weight of the gun was for
drop safety )
TCB