The show has a bit of a "Twilight" feel, with generally better writing, and without the high-school romance. There is some love-triangle stuff going on, but it is not as dumb as Twilight could get sometimes. The show definitely pushed the boundaries of what could be shown on basic cable in terms of violence, nudity, and sex. The DVDs actually have more nudity than the US broadcast did because most of the butt shots (mostly from the males on the show, but also quite a few from Laura Vandervoort) got edited out on the US broadcasts. The series is made up of relatively unknown actors (at least here in the US) which included Greyson Holt, Steve Lund, Greg Bryk, Michael Xavier, and Genelle Williams.
The first season is really about the pack versus Mutts (werewolves that do not belong to a pack that are forced to move around and never put down roots). The second season is basically a wolf versus witches theme, with magic being introduced into the series, and the third season has a pack vs. pack theme. The set is just the DVD released for the three seasons packaged together, and the extras as just what was included in the individual season releases. There are no special bonus features that just come with the complete series set. Each season has some deleted scenes and at least one behind-the-scenes featurette. The second season also has a 45-minute portion of the NY Comic-Con panel, and an episode of an aftershow that aired in Canada.
Overall, the series is good, but a bit predictable. It is definitely not a family-friendly show as there is a lot of violence, some swearing, and a lot of sexual content (and as much nudity as they could get away with). The sexual content decreases with each season, but the violence is prevalent the entire way through (and it does get quite bloody). The series is well-written and acted. It was adapted from a set of books, but I have never read them so I am not sure how faithful the show was to the books. I would say that if you are a fan of the sci-fi/fantasy genre, it is worth checking out, whether you stream it or pick up the DVDs. Note, that the first season is available on Blu-Ray, but at least in the US seasons, two and three, and the complete series are only available on DVD.