Ace Attorney 4 - 6 aren't very good.

I liked 4 more than most, not a slam dunk but pretty fun and got some very cool (if weird) moments.

5 has pretty bad writing but did give us Blackquill so I wont call it the worst.

6 was honesty disappointing for me, just didnt like most of the characters, hated the seance mechanic, and just wasnt very satisfying.

yeah Id love to have nearly the whole collection in one place, but its hard to imagine replaying Dual Destinies or Spirit of Justice being any fun.