I did flight simulators for years before I started, and all it did was cause me to look at instruments when I was supposed to be flying visual once I started for real. Mind you my instructor was astonished how quickly I was able to get a hang on setting trim and some other progress, so maybe it does help have a better understanding when setting out.
Useful for practising some procedures and getting a handle on what is to occur in a lesson, but just so far removed from actually having the aircraft in your hands its hard to bring more than that to it.