I prefer the FAs to the PAs in every single color. Yes, as a black cap toe the FA is technically a hair less formal than a black PA, but in the real world it's completely irrelevant. The punch cap adds just the right (minimal) amount of flair and distinguishes the wearer from the hordes wearing black stitch caps from Bostonian, Rockport, CH, etc.
I'm starting to feel this way about the PA. I have black PAs as well as 5As and I'm thinking about selling my black PAs. I never reach for them except when I was a groomsman which is probably the only time now I'd wear it over the 5As. Brown antibe PAs might be hitting the bay shortly as well. I have 3-4 pairs that aren't listed in my signature I'm going to be selling too since they either don't fit me great or just don't make it out in rotation. Started out with PAs and now they are on the chopping block.