Some of the music is terrible in EBA, really terrible - I'm not sure how its been accepted so readily by fans of Ouendan to be honest. There's one song that I just cannot get past because it's so...bad/doesn't seem to fit in properly (Let's Dance, for those interested...). There are some excellent choices that fitted in well - YMCA, Material Girl - but others just totally wreck the experience when compared with the likes of artists such as Asian Kung Fu Generation and Tomoyasu Hotei in Ouendan. If they aren't changing the music for the European version it's been a waste of extra development time.
I like parts of EBA more - I have found it to be funnier in sections (partially due to being able to understand the language, though it was easy to follow what was going on in Ouendan anyway), and it has some useful features such as skipping to the start of the gameplay (something that could grate on the last level of Ouendan, since it was pretty difficult and you'd have to sit through a minute of build-up before attempting it again), and I hope they've brought some improvements over from it to Ouendan 2, but the original concept and execution just has so much more charm and feels much more concrete to me.