the whole style of play is different. in the BPL, you have fast, thin, good, players who flop a ton. and the Bundesliga, you have the "hidden-gems" that are total beasts (Ivica Olic, Esswien, Diouf, etc.) people in the Bundesliga are all really tanks. they do flop, but that is every league. but the style of play of the Bundesliga is more aggressive, and full of total tanks. just watch a few games and compare them to the BPL. that is what i think.
Went to Dortmund at the end of the season to watch the game against Hoffenheim. Incredible atmosphere. The 'Yellow Wall' in full voice is truly something special to behold.