My PS3 works juuuuuusst fine.
The game looks great, it's fixed a multitude of issues I had with 3.
As for it being the best in the series, 2 had a tremendous story and really launched the series in a great direction with 2 follow ups that were great/good. There is SO MUCH TO DO in this game, and it is ALL good. The city stuff is there, the tombs, the forts....
I hated the naval battles in 3. I LOVE them in this. I spend more time on the sea than on land, especially fighting other ships. So many variations on different battles.
Get it for PS3, play it and then pay the $10 to upgrade on PS4.