I'd thought the Rohrbaugh was heavier, guess not. It is not +P rated. The PF9 is rated for "limited +P use". I carry +P in my P11.
I bought that P11 when there were few other choices, was the innovator as little 9s go. Between the PF9 and the P11, I'd go for the thinner gun since the firepower isn't that much different, a few rounds, but there's not enough difference in the guns IMHO to switch. I'm perfectly happy with what I've got.
Rohrbaugh? Well, if I hit oil on my property or the lotto works out for me, maybe. I do prefer +P stuff, though.
I'm not sure if ANY of these little 9s are +P+ rated. Maybe a Kahr K9, all steel pistol, not really a pocket gun.