The characters are pretentious, the story lines ridiculously out of touch with reality, and the acting is pretty poor.
First, the lead character, is definitely easy on the eyes, but acting abilities...not so much. The show itself, seems to have zero fact base in what the FBI does and mixes it up with NSA/CIA type operations, and on top of it they would like you to believe that FBI recruits come out of the academy, with super human abilities, super human intelligence, and are immediately given positions above all those serving in the field for many years. Not to mention everyone in the academy is a terrorist, has terrorist ties, is a suspected terrorist, or has some desire to act as a terrorist. Apparently the TV FBI is worse at vetting than a potato.Apparently Quantico is just a college dorm full of annoying but cute children, the only thing missing is STD's. Or maybe the pretty is all that matters...
The show focuses around one agent and it is as though she is the complete center of the world. At first this fits because hey, every show has a star but this show does it in such overblown annoying way that you just scream "WTF!" every 2 mins.
Excessive dialogue is used to cover shoddy acting but that actually makes it worse. The only thing this show has going for it is pretty actors, and a fast pace. Other than those 2 things...it's crap.