My wife has a P3AT and loves it! I've shot it and bought a P-11 for myself, instead.
The P3AT fits fine in any pocket while the P-11 is a little bulky for jean-shorts. (Great in cargo-styles, though.)
My wife can shoot the P3 just fine, but I found it "jumpy" in my hand. (Hense the P-11.)
The triggers are long and heavy compared to S/A semi-autos, but remind me of a good ol' revolver trigger. (Which I like.)
Remember, these are personal protection guns, not Gold Medal Target Master Range Pounders. They're made for up close defense. (Even KTOG's postal match is set at 5 yards and 10 yards respectively for this gun.)
If I had to go with either KelTec's P3AT or Ruger's LCP I'd go with Kel Tec. (Sorry guys.) It might not be a "finished" as the Ruger, but Kel Tec has years of experience with this type of gun an will easily fix any problem you might have. (I lost the teeny-tiny ejector piece on my wife's P3AT while cleaning it and Kel Tec shipped out a new one free no problem. PS: The LCP has the same teeny-tiny piece.) The LCP is a new design for Ruger, and the owner's are still getting used to the compromises that come with it. They're getting good, though. Kel Tec also has a huge group of people with tons of knowledge about these guns.
http://www.ktog.org/cgi-bin/yabb2/YaBB.plIf I had a choice between the P3AT and the Kel Tec PF-9, I'd go with the PF-9. Yes it would be harder for me to shoot than the P3AT (Roughly the same size and weightas the P3, but with a larger kick due to the 9mm round.) , but the cheaper cost of the 9mm round will afford me the opportunity to practice more.
To be honest, if you are out and about in shorts, you are not going to go wrong with either choice of P3AT or LCP. They may not have the magical "4" on the caliber case, but they get the job done.