I think they are cool and one of my dream set ups is a 9mm AR that takes glock mags.
I would have no problem with one as a bedside gun. If I remember right sub sonic .300 has similar ballistics to .45, so a .45 carbine should be plenty useful.
I CC pretty much all the time im out in public. I will OC around the house and if I have to rin to the store I pull my shirt over the gun. It will print like crazy but its still covered.
I used a place a few years back beside town center mall. I'll only use otter box cases now. I've dropped my phone a bunch in am otter box and its always fine. I had an iPhone in a magpul case and it broke the screen the first time it dropped.