They had side quests you could complete on a hunt, and if things went wrong you could complete the side quests and finish with those, but for tiny rewards. And in some missions, they were required. I'm pretty sure those aren't in 3U, anyway. On the plus side, though, they added all of the weapons they took out for tri, like the dual swords, hunters horn, bow thing, gun lance, and I think that might be it actually. Unfortunately, I think they took out the event calendar, which was cool because you had to do events when they rolled around, and when Jhen Mohran rolled around, it was time to celebrate. Now event quests are handled like free DLC I think? I dunno, really. It's more convenient though, since you don't have to wait a month to do something.