I like the idea of this as a hiking / survival pistol. Light gun, light ammo, and even if you forget to take a box of spare ammo with you, the gun itself holds 30.
EDITED TO ADD: Yeah, as drtybykr said below, it will be LOUD. That's a plus in my opinion, for an emergency signaling scenario. If I were lost in the woods, I might pop off a couple sets of 3 rounds in a row whenever I thought rescuers were within hearing range.
I like the idea of this gun as a home defense weapon for a beginning shooter who is also very recoil-shy (of course not all beginners are). Naturally .22 magnum out of a handgun barrel is not going to have a lot of knockdown power, but it should have good penetration and if you hit the right structures in the opponent's body, you'll get the results you need. It's all about bullet placement. And with a fast-firing semi auto that holds 4 times as many rounds as most normal handguns, you can put two rounds center-of-mass in the same time another shooter with a hard-recoiling gun would only get one hit.
I have never seen the PMR-30 in person, though. I'd like to rent one and shoot it at some indoor range in the Atlanta area if such a place bought one for a range rental pistol.