I prefer the Kel-Tec although there probably isn't a nickels worth of difference between the two. If reliable either makes a great always gun. I know that I have had complete reliability from a K32 and 2 P3AT's over about a thousand rounds of practice so why switch.
RickN....I bought a Super Blackhawk at a gun show for a song..it was badly abused..ejector rod housing off, stud pulled out, back sight smashed from being dropped, and on and on.
Sent it to Ruger. Expected to pay a couple C-notes for parts/labor. Got it back in about five weeks, new barrel, sight, ejector rod/housing, grip frame screws, some internal parts PLUS a polish and reblue.
NO Cost. Other than shipping.
Don't know if they'll still do it on your friend's but would bet on it.
I own a half dozen or more Kel-Tecs. The P3AT is great. I have no reason to buy the Ruger, since my Kel-Tec works quite well. I have various other Kel-Tecs and they have all worke well after breaking them in and sorting them out. They look very close, so I'd probably say go with the least cost. My PPK/S is dying from loneliness. It took a LOT to make it reliable and it is twice as heavy and bulkier than either the Kel-Tec or the Ruger. My one suggection would be to take a serious look at the PF-9. It's a compact 9mm and has a little more of an effective cartridge. The recoil is about the same. It's flat and hides well, plus it's a real 9mm.