The 80 hours is arguable (as I managed only 40 hours for the True Ending on Normal), but should you decide to pursue maxing out Social Links, taking out the Reaper, and beating the mega-powerful optional boss (as in more powerful and annoying than the True Ending boss [although not QUITE as annoying as P3's optional boss]), not to mention going through New Game+ for some extra fun (being what brought me over 100 hours of enjoyment to date, though I haven't booted up my PS2 in a while), you can very easily stretch it out.
Anyways, back on P4A: first, you should take a look at Elizabeth's Instant Kill. Second, that fightpad is a wonder to see. Sadly, it may never make it out of Japan without importing. I really hope to see that kind of thing stateside instead of just the very limited Persona 4 Golden pre-order bonus. (It's a very smexy Vita skin with accompanying wallpapers.)
[Off-topic about the topic now, should I just change this to a P3/P4/P4A/P4G thread instead of just P4A? All of them are wholly connected anyways, even if P3 and P4 were related only loosely until P4A.]