I like this Anime. While it's not the best thing out there, it certainly isn't the worst thing either. It borrows A LOT of elements from other Anime like Trigun for example, both main characters are bumbling idiots to hide their 1337 skillz. Plus there is also a number of uncomfortable similarities with Hellsing and a few other Anime's. While that may turn some people off, at least give it a watch before writing it off completely.
One thing that bothered me was that the ending suffered that same unfinished rushed end of story that most Anime now adays seem to suffer. Beserk being a real good example of that. however it should be noted that the creator/writer of the series passed away after it was announced that his pride and joy novels were to be made into an Anime. So it's likely they didnt' have any information to finish the series, I dunno. It just seems like they could of went on with the series and shot from the hip. We shall see I guess.
But even after all that I give the series a 3.5 out of 5. There were some great story elements in the Anime that just never got explained and that really bothers me, but meh I guess I will have to live with it.