I should note that the show is much darker and gorier than I expected it to be. Episode 2 might be the goriest screen-whoniverse work we've had, but it was GOOD so it didn't feel vapid for it. However, I'm not kidding that its a surprising amount of gore. Keep that in mind if that's not something you want yourself or others to see.
My favorite character is Ram Singh by a longshot. Fady Elsayed really gives the standout performance here, and he's someone we should be watching in the future. He has a promising career ahead of him judging by how stellar he is here. The cast as a whole is very good, and all do a good job with their characters. They don't all come off as entirely three dimensional at first, but they sink into their roles. Katherine Kelly pulls a surprising amount of dramatic weight into her role as Miss Quill, who is playing the role that would be filled with Sarah Jane, The Doctor, or Captain Jack in other whoniverse shows. Thankfully it isn't played straight, and she adds a rather large twist to the usual format that makes the show feel (thankfully) very different and unique.
Oh, and the protagonist Charlie has a boyfriend, who I hope we see more of cause the boyfriend character is super sweet.
Probably what I'm surprised most about is that this show is far closer to Torchwood on the spectrum of Doctor Who spin offs than the Sarah Jane Adventures. Characters have been cast into a terrific situation, but it is terrifying. There are wonders, and they are the same thing as horrors. A lot of time is spent on character growth, and dealing with the effects mentally and physically this stuff has on the characters.
In short: its worth your time, its well done, but its VERY much not for kids.
Oh, and I like the themesong.