To me the battles are so lame and the main characters win because of a sudden power up never stablished, that is specially grave for an arc that bases itself on battles. The antagonists are far from being the best ones we had saw until that moment. The end is completely absurd, the worst thing Oda has ever done in my opinion, a not crewed ship goes to save his crew alone and if that were not enough, it has the value to talk while burning.... It is just.... stupid and it does not make any sense.
I have more reasons to dislike Enies Lobby arc and consider it a bad one but this are the main reasons.