I just caught the first episode of this on netflix the other night as I was bored and looking for something to watch.
Long story short, 12 hours later and I've watched the entire first season (24 episodes) in one sitting.
I'm not a huuuuge manga/anime fan but I watch the odd one here and there, and this is easily one of the best I've ever seen. If you are into your anime's and havent caught this one yet, I'd definitely recommend it. I won't give anything away if you haven't heard of it, as I went in totally blind and I think that way gives it more impact.
I liked it well enough, but not enough to understand the hype behind it. I'm anxious to see where it goes in the next season.