For me it is the other way round lol. I think it depends a bit what you play the game for. The combat or the roleplaying/strategy part. The later is better in WB, the former profits of the better graphics, sound and animations of BL. However I have to say whilst I can see the merit of some combat changes like for exemple the ability of horses to push infantry aside (friend or enemy) and multiple block directions for shields, the fact that it is this unbalanced and akward in parts makes it unplayable for me.
Also, BL has larger battle sizes, a more modern UI, more epic looking sieges (although i'm still waiting for siege AI fix... lol)
And I also like the idea of perks, smithing, trading, etc, but more balancing is needed.
It's true that I care less about the roleplaying aspect - in warband i always felt it was a pain to take walks through villages just to find a guy to talk to, and i would rarely read long dialogues and stuff like that.