I just watched this because a guy I work with came in raving about it today. It should be noted that other than Game of Thrones and the two Walking Dead shows (not saying those are good, but still), the extent of his viewing is usually stuff like Ghost Hunters and those History channel mockumentaries. So I was already a bit hesitant of his review. He insisted that it was as good as Game of Thrones, maybe even better. It isn't, not even close, but you guys probably already knew that without even watching it.
It wasn't the worst thing I've ever watched, but like the others above I can't really muster up much excitement to watch the subsequent episodes when they come out. Since I haven't watched anything but the pilot of Vikings yet, I feel like I might as well just catch up on Vikings every day this is on instead, because that is a vastly better show (at least from the pilot and word of mouth). If you've already watched all the other shows like Vikings and Spartacus, and you are really bored, I guess this wouldn't be a terrible choice, but it was so predictable and uninteresting. You could almost see where the writer or director said, "Ok, this part is getting a little slow, let's toss in something bloody to liven things up quick." I mean, some of it was warranted, and I'm sure they would say they are just trying to depict the reality of the times, but it came across as contrived and trying to one-up GoT most of the time.
5/10 perhaps, if you have nothing better to watch. Very soon I will, so it will be tough to keep this in the rotation unless it gets drastically better.