IMHO, a better option for somebody who wasn't comfortable with a 5.56 and was looking for something in the PDW class would be the good ole M1 carbine with a folding stock:
The first thing people say when they pick it up is they can't believe how light it is.
The first thing people say when they shoot it is they can't believe how tame and accurate it is.
Hornady is also now making their Critical Defense loads for the .30 carbine:
Prvi Partisan has the soft nose rounds at $.50 per through Widener’s. But for home defense in a rifle round, I prefer the 5.56 in an AR pistol with 11 inch barrel. If you need to use it at more than fifty yards, the tube from a shop vac slips over the buffer tube quite nicely.
IMHO neither the 5.56 nor M1 carbine have any recoil; however, I have a 15 yo daughter that loves the M1 and hates the AR (noise too loud), conversely my 12 yo daughter loves the AR and says the M1 kicks too hard. It’s not logical, but its real.
This is probably the most important thing about ammo for the M-1. The old ball ammo wasn't that effective. Better than a pistol, but not much. I'm going to get some of that new ammo for my daughter's M-1.