Good, but not really credible The show is enjoyable, the plotting and dialogue competent, most of the acting above par, the characterization of the main character well-realized, and most of the others acceptable, but....
The reason for operating in 2 completely different time-lines is inadequate structurally. Dramatically, it allows for the desired level of tension and suspense, but the device is truly over-used. If you wish to make a story more complex, please simply make it more complex; adding a future (or past) time line requires a very demanding adherence to the integrity of each time line, as well as a strong reason to do so. I don't think it works here.
Various integral plot elements are likewise manipulated - often with realism as the hostage. For example, the dialogue between FBI agents right after the "capture" of the lead, is very odd.the line: "Let her figure it out", prior to the arrest didn't make much sense at the time, and in retrospect, makes even less.
At a more basic level, the amount of duplicity surrounding most of the new agents, as well as the levels of duplicity surrounding the recurring staff members, is quite over the top. The apparent argument between the writers about whether the trainees all have done a mission as an amateur agent, or not leaves me with a bitter taste.
I dunno, I did get captivated by the show, and any show that does that is probably worth seeing and recommending, but the ongoing strain to my credibility "shocks" me out of the fantasy too often.