I've recently tried 510-Pyro and compared it to some film developed in XTOL. I took some pictures of the same subject (some Canadian Tire money and a Kodak grey scale separation guide). I shot APX 100 at various EI to get a good cross section of shots. I wanted the comparison to give me clarity as to the qualities of each developer.
I developed the APX 100 for 9 minutes in 510-Pyro and 9.75 minutes in XTOL. I found the results interesting. Upon inspection, the XTOL film seemed to exhibit finer grain but when printed, my friends were split as to which was less grainy, the XTOL prints or the 510-Pyro. I definitely preferred the blacks of the 510 formula and gradation was better. As for sharpness, the 510-Pyro was noticeably sharper.
All in all, I was very happy with the 510-Pyro and will use it as a film developer. Oh, it can develop paper too.