I found the first few episodes a bit silly, and watched them only for good ol' Amanda Tapping, because I wanted to see how she's doing after the deep hole of Stargate cancellation, after I saw her a few seconds in Stargate Universe.
Luckily she found a good new home. As she is involved as a producer, we can hope that she will do everything to prevent early cancellation.
The show itself, as I said, did not quite satisfy me in the beginning, but after say, four episodes, I got used to it. There are some enhancements, and some positive surprises. The biggest surprise is Christopher Heyerdahl, who plays the bad guy, turning into the good guy, and also the monster butler bigfoot. He is in all positions very convincing and obviously a good actor. We can see which potential he had as the Wraith Todd in Stargate Atlantis. Everyone who casted him here had a very good idea.
I must admit, that a big part of the show is simply childish, but it is made with much love and effort, and it is professional, fast and thrilling, given that the viewer will adapt to the completely impossible, not to say stupid, plot. It was interesting for me, seeing myself accepting all those monsters and vampires for watching a good ensemble. What I also felt is that here the people try to pass their enjoyment for doing their job to the audience. Production values seem not so high, but I never had any cheap impression.
Amanda Tapping is not that big Actor, but she has charisma, and she is holding the family together. Again, she is the good and honorable guy, here with some secrets behind, which aren't too ugly to blame her. I think, she could need a couple of real sins, maybe they will come up later in the show.
For now, I can recommend the show to everyone who likes solid acting, nice monsters and (mostly) sympathetic characters, all brought together with English manor atmosphere and sets, kindly broken by welcomed exceptions, like the humorous (but bloody) episode 10 of season two, where we meet one beautiful cylon from Battlestar Galactica. However, you must be generous, because the script writers aren't masters of quality control here.
After season two, ep. 07, and I had to lower my voting, because the spirit of the new is unfortunately gone. After the victory in the war against the Cabal, who attacked mostly ridiculous and silly, the authors and the characters have obviously a lack of ideas what to do. Routine has come to the team, and they became a little lazy. Tesla and John Druitt both disappeared with no further explanations, I don't like such unfilled holes, especially if they are essential. I hope they will do better in the future, otherwise they will not have one bright. Now, after ep. 10, there was finally the return of Tesla, which raised the fun immediately, esp. after a number of really boring and silly episodes. The episode with former SG-1 Tapping's Co-worker Michael Shanks was (for me) the worst.