Kel Tec shows a with of .77" for the P3AT and .88 for the PF9....if 0.11" is a deal killer. I really don't have a problem with width of the gun, but it's mostly do to my wardrobe. I pick it that way.
I do have an alternative to my 1.0" thick P11 and slightly thinner Grendel, my new to me P64 Polish Radom. It's about the same width as the PF9, but ballistics are closer to .380 than 9x19. Still, I like that gun a lot and if I need thin, it will fill the bill.
I can say, that Radom carries IWB a little more comfortably than a thicker gun like the SP101 which has a lumpy cylinder and even the P11 is a little more noticeable IWB, but not much. Either carries well pocket or IWB and I usually find myself going for the 9x19. Both are accurate, reliable firearms.