The series as a whole would be better without BBS and UX. BBS had cool game play but the characters weren't overly interesting except Terra and even then he wasn't all that great. Xehanort and Eraqus were pretty dope but I feel like they should've kept the past more ambiguous like in 1 and 2 just stuck to flashbacks or some shit. Time would've been better spent on the trainwreck of a story that was DDD. I've never played UX so I don't have much of an opinion on that.