Release: Feb 2016 (JP), Sep 2016 (NA) Time to complete: ~60 hrs
I put this game on hold to play Persona 5, and it's interesting how much I liked going back to it afterwards. Persona 5 had the best battle mechanics of any of the Personas I've played, and yet coming back to SMT4A was like having strategy unlocked. The breadth of skills and amount of options available in general are far more tactical and appealing than anything in Persona.
SMT4A is set as a true follow-on from SMT4, in that the scenario continues on from one route of SMT4, but your group of characters is different (although there is cross-over at points). What might not be so appealing is that the main characters are young teens, although I didn't find them annoying at all, and actually quite liked the cast in general. Surviving in a Demon-infested Tokyo isn't easy for adults, let alone children, and these ones certainly go through some gnarly stuff. I actually liked the story and scenario in general a lot, and the boss battles are an improvement over SMT4 in my opinion - the ultimate boss in particular is drastically better than the pathetic anti-climax of SMT4. I especially like the differences in the final boss battle depending on your choices during the game - definitely worth beating with both main routes, in my opinion. The play length was much more to my tastes than P5's 100+ hr campaign, also.
So what of negatives? Personally, I have none. The 'world map' and general 'quality of life' have been vastly improved over SMT4's somewhat clunky-in-places design. Music is fantastic as usual, your allies are EXTREMELY less likely to be harmful rather than helpful (and you have choice over which ally you take into battle), and while the general view seems to be that the last two dungeons of the game are fairly tedious/labyrinthine and overly-long, I didn't find them so, since I was always making progress. I tend to greatly dislike such things in games, but found these examples just fine... your milage may vary though.
So in general, this has been my favourite of all the Persona/SMT games I have played... but would definitely recommend playing SMT4 first - as much as I liked it, you certainly won't be impressed with some of the mechanics of the earlier game if you were to play it afterwards, and this is a sequel, after all.