That wouldn't make the Falcon itself any faster which is what he was trying to state. That would make him a better pilot/navigator and relate nothing to speed/time.
Depends on the shortcuts he took. Could have been obstacles that only a very fast ship could get through, whereas a slow ship might have been sucked into a black hole or smacked by loads of asteroids or attacked by a horde of angry space-nerfs.
I prefer to just go with the 'it's a film and sometimes you've just got to go with it' approach. If I was bothered about scientific fact in my fiction, I wouldn't read as many comics as I do.