It's pretty good. I wouldn't schedule my life around it (as, sadly, I do with Bones), but I catch it when it's convenient. I agree that Nathan Fillion is perfect in his role as a roguish womanizing mystery author. Stana Katic-- I'm a little iffy on her. She plays the cop REALLY well. I'm having trouble seeing the woman-side of her (and thus having trouble understanding why Castle wants her, unless it's just becuause he hits on every attractive woman in his sphere). However, the next new episode includes an ex-boyf of Detective Beckett's, so maybe she'll grow on me.