The SUB guns are not inherently flawed. It is just much more important that they leave the factory properly fit and configured and with the correct magazine & recoil spring weights.
There is no reason why they cannot function (feed and eject) just as well as the longer pistols.
That fact was proven Many Years Ago when the custom gunsmiths radically CHOPPED the full size .45 to even shorter lengths than the ones being "factory produced" today.
If the machine work is good...and the barrel throated properly...and the "breech face" smooth - with a tuned extractor...then they should function just fine.
Logic dictates that "smaller" is ALWAYS easier to conceal than larger.
That fact just cannot be argued. Ask the CIA or KGB about that.
PROPER holster selection is much more important than many folks realize.
That is why those of us that have been carrying for many years have a closet full of holsters.
That is because (years ago) many holster styles sucked for good and proper concealment.
Thank God for the holster makers of TODAY who refined holsters to the point where concealing a full size pistol is now actually a pretty easy thing to do.
People absolutely NEED to buy a great holster AND...AND a good thick stiff Gun Belt.
One does NOT work without the other!
The very best holster will not work with a crappy belt.
Holster - Belt - Belt - Holster ~ They are like Brother & Sister ~ Mom & Pop ~ Rum & Coke ~ Adam & Eve ~ Rogers & Hammerstein ~ Simon & Garfunkel ~ The Devil & Mrs Jones.
You need both to properly conceal a large firearm.