I stick to a single save as well. I enjoy living with the consequences of my decision, and don't have much intention of replaying to see the different outcomes(i know of most of them anyway). Although occasionally i make a new save to check out a few obscure events(like the game over on the train in episode 3) but my first save is always my only playthrough.
The only time i ever tried to change my save was when Carley died. I immediately jumped back to try to do anything to keep her alive but i knew there was nothing i could do before the scene even started playing again.