From what I've heard, the holder of a PA non-resident LTCF has the same rights in Philly as elsewhere in the state... until the police get involved, after which you might have a problem.
IANAL, YMMV.
I carry in Philly every time I go there. I always keep in mind that the Philly police really dislike armed civilians, and will likely try to screw me over if I end up using my defensive weapon.
My son lives in Philly. He's an Iraq combat vet who has cleaned up -- and created -- more mangled bodies than you want to know about.
After the interview at the Philadelphia County police for his LTCF, he threw up.