Okay so budokai one totally screws up the story and it is very short.
You can beat the story 100% meaning you playing through the whole story then play the hidden story missions after within an hour or so.
Budokai 3 is pretty long and a huge improvement from the first but unfortunately I played this game way too much when I was a kid and I'm still burnt out on it.
Within the first hour maybe I was bored but I still pressed on and beat the story mode with all characters and unlocked everything except for cell jr and saibamen.
Anyway I do recommend people pick this one up because it is a great pack but I just couldn't get into it since I played too much when I was younger.