There is quite a bit of added depth watching it a second time. I don't know if I will go ahead and rewatch the whole thing now - I just wanted to introduce it to Jenny - who loves it - particularly the gory surgery bits - she just keeps stuffing her face with Chinese food and watching the blood flow and splatter. Nutty, horrible woman.
I usually like to wait 5+ years before I do a rewatch but now, even though it just ended last year I think, I might be hooked in.