I wish I could get into these beloved games, as stealth is likely my favorite genre. I've tried and I think there is a lack of tension in the idea that you are meant to do an initial playthrough of a level, unlock all it's secrets and then go back to perfect the assassination. I suppose that misses the main ingredient I enjoy in a stealth game which is having your back to a wall, thinking on your feet, and improvising a way out under extremely tense circumstances. Something about Hitman seems to steal that feeling away from me and I wonder if it has to do with the design leaning towards unlockables and replayability. Not that I don't enjoy replaying my favorite games.
So yeah, it misses the mark for me, but clearly they are masters at their craft over at IO, so I'm glad the rest of you enjoy what they're doing. I'm hoping the James Bond game will cater to my tastes.