I'm slowly dragging myself through the first series, but I'm not sure what to think - in parts, it's fantastic (the episode with the Gentooan girl is a particular standout, for example), but then it descends into immature humour that really makes me want to turn it off.
I really want to like it, and I feel like I ought to (it's from the guy who did Cowboy Bebop and Samurai Champloo! How can I not like it?). I don't know if I'm even going to finish it.