I pre-program techno sets sometimes, when it's a big, big event for me and I know I have to play well + I'm sure that the music I'm going to play is going to work for the crowd I'm playing to. But I only make sure the records go dynamically - i never plan mixes, cause if records jump or you miss a planned mix, you're screwed.
But I have a formula with trance that means I KNOW 100% if a record is dynamically going to go with another even without hearing the full record all the way through (it takes me the best part of an afternoon to categorise my box each week to fit with that formula mind you!). So I don't need to pre-program any of my trance sets.
I can't see anything wrong with having your favourite mixes and trying to redo them on a regular basis. I do this all the time...but just be prepared for things to go wrong!!!