I'm an awful human being and always forget to check forums so this answer is SUPER late. For that I'm super super sorry. Overall I would estimate that the PS3 version is about an hour+ slower than 360. There are several reasons for this:

-enemies on PS3 start on the same stats they have in 360's Encore Mode (50% extra everything) -PS3 has a couple extra areas and tweaked boss fights that would add time -PS3 photos sell for about 10% of what they do on 360, so you need a LOT more photos -PS3 EXP is extremely nerfed with many bosses/enemies giving 50% or less of what they do on 360

There may be a thing or two I'm forgetting to mention, but for these reasons alone, nobody has really routed the PS3 version yet and it would be substantially longer and more difficult.