I think people are underestimating McGregor. Yes, he isn't a boxer, but he is a fighter, in the prime of his career, and one of the best at what he does. Plus, he's got the bravado and confidence not to psyche himself out. He seems like a natural at fighting, which means he will probably warm up to boxing quick. I don't know if he'll win, but I don't think it will be the wash that some people are expecting.
I thought it was okay, but not as good as I was hoping for. Honestly, I think they focused too much on the "stereotypical evil church" stuff. It was just cliche and repetitive. However, it was an alright start, and Alucard was cool. The last fight was also pretty dope, except for the incredibly abrupt ending. Barely even felt like a whole season. But I'm curious to see how Season 2 turns out.