Personally, i prefer Revelation's maps.
I think they are stunning visually. I love the exotic atmosphere and diversity of the maps. I prefer the more middle eastern / oriental style Revelation's maps have to offer than Brotherhood. I think in Revelation's the art direction si going well in Sp and MP, combined with interesting colour schemes and different atmospheres i think they are superb.
I wish to be honest that instead of focusing on Brotherhood's multiplayer maps that they would have focused on Revelation's maps for the first multiplayer experience.
I mean for Souk if you ever look at the outer edges, you can see winding houses with a more organic and interesting atmosphere than some of the Revelations maps potray.
Although, i do agree with Serrachio that the hookblade is a problem.