Out of all the shows I watch that depict law enforcement and/or Government agencies, this is the only one where I really have to suspend by disbelief to watch it. To think that they'd let Spader's character roam free in between cases is a little hard to swallow.
That said, I really love this show. I think it's one of my favorite new shows of the season (along with SHIELD), I'm really interested in finding out why Reddington is so drawn to Lizzie (I'm thinking he could be her father...but that might be too cliche).
Incidentally, NBC picked this show up for a full season, so we'll at least have it for a while (unless the ratings tank really hard in the next few months).