Sure, it isn't Supernatural. But if you want more and some other point of views or a bit more back story...and if you like anime..then give it a shot.
It isn't 60 fps like other animes though, it is what I would call 'choppy' and the use of black/white a lot of the time and not being actually 'noir' might turn some people off, I found that bit of animation kinda cool. The fact Sam is actually voiced by the real Sam makes it a bonus and the voice actor for Dean sounds pretty spot on is good enough for me.
Don't expect to be blown away or anything but if you are a fan of SN and aren't going to judge harshly then definitely give this a try. If you like both than you will probably enjoy this show.