what i hated is they rushed our favorite part of BBS
the "fight" between MX & Vanitas vs Terra Aqua and Ven
Compare KH2FM Secret Ending to the scene in game. feels dull
Remember, CG cutscenes take up a lot of space. It was much more worthwhile to have it as real time (and I prefer real time more than CG cutscenes because of consistency).
Overall, I actually thought Birth by Sleep beaten my expectations. But my expectations for it was low (compared to others, which were extremely high) because I was burned out by 358/2 Days and Kingdom Hearts II. Sure the story wasn't well-executed, but when the last two games had terrible storylines, then this game is a big step-up in terms of its story. It doesn't beat Kingdom Hearts and Chain of Memories, but for the worse of Daisuke Wantabe, it's actually pretty good (well... the worse of Daisuke is Final Fantasy XIII, but....)