I played the original and I still loved #3! They were not ripoffs they were 'flashbacks'. Basically the entire game is flashbacks of missions leading up to the mission you are currently on. Some of these flashbacks are things you hadn't had a chance to participate in and some of them are ones you did already participate in.
The redone missions were redone very well. There was no silent assassin mode in Hitman 1 so killing a ton of people was never really a problem. But this time around, I had to do those older missions in silent assassin mode, which added a whole nother aspect to them.