I'm with Hellenic. If there's some reason for me to suspect I may have to change orders, I'll save, but otherwise, I just finalize. I'm in a game now, one person in a gunboat game has to retreat with 24 hour phases. Does he finalize? Noooo.
As for phase lengths, I wish there were, like, emergency buffer zones. So like, 12 hour phases with 12 hour emergency buffers. So in the first 12 hours, you can save, finalize, whatever, but after that, you can only finalize. When I play a 24 hour game, it's not because I want every turn to be 24 hours. It's because I expect that at some point someone may need that 24th hour because of an isolated emergency situation. Otherwise, I appreciate early finalizations.