I've been favouring 4's alot recently, and my latest acquisition has reinforced the fact that I am more confident on 4's full stop. Though, I compensate by tuning a full step for more growl and those few extra lower notes, but I do still have a hankering for a good 5 string though.
The only 5's I know that sound different to it's 4 are Thumb NT's, and that's mainly down to the pick up placement.