I think this show is better than average, and I do enjoy aspects of it, but there are many ways in which it can improve.
First of all, the characters are all fairly well-rounded, multi-dimensional people. Most of them are developed well with multiple aspects to their personalities (not one-trick ponies, such as the characters on Criminal Minds). The storylines so far have been interesting and have kept me coming back.
The negatives, however, are glaring and can be improved greatly with time. I find the dialogue to be very poorly written and extremely unrealistic. I've never met a person in my life that talks to people like they do. The best written dialogue makes you believe the show could be a slice of everyday life with realistic interaction, not dialogue that sounds like it came straight from a 1990s action flick. It reminds me of the dialogue in the film Speed.
Also, although I like Aaron Tveit as an actor, I do not believe he was the right choice for this character. He looks like a typical upper-class Caucasian New England university student, not a man with experience working as a bodyguard for drug dealers. I highly doubt any criminal would hire someone who looks and acts like him to work for him. In my opinion, they should have switched his role with that of Manny Montana's, who I think is much more believable in the role as a drug lord's bodyguard.
I also don't think it makes any sense for undercover agents to be living in the community they are supposed to be working in. Most people I know who work in such a capacity live well-removed from the community because it lessens the chances of their cover being blown.
Update: I have continued watching the show into the second season and it has gotten better. I think the actors have grown into their roles in seem more convincing. At the end of the first season, the show became very unpredictable and that keeps me interested. In fact, I think it is the least predictable show on American TV right now. So I upgraded the rating to an 8.