If that's your given intent, sounds like it'd be nifty to have. Low power of a pistol for HD+easier to use in a dazed state (you're probably not going to be 100% alert in HD scenario, if you're awakened). That, and 9mm=fun on the range, expecially if you have a compatible 9mm pistol to accompany it. Sure, someone will rail "shotties only", or "newfangled piece of junk", or "overpriced", for any HD weapon, or some such--I've handled them, think they're nifty, and I'll probably buy one at some point in the future (granted, there's other things in line first, but at some point it'd be nifty to take a carbine and a pistol to the range, have 'em use the same mags, and only have to take 1 type of ammo).
I'd say that if it's compatible with what you have, and you have no qualms about how it would work in the process of clearing your living quarters, go for it. Just don't necissarily let all the negative responses on here sway you from buying one--a SHTF mega-rifle of doom it's not, but it would fill an interesting niche in a collection.