I use flight sim 2004 fairly regularly but never regarded it as an aid to training. I am a meagre PPL(A) holder with no additional ratings (yet :-) )
Where simming has helped me greatly is with understanding the basics of radio navigation as well as giving me a much deeper appreciation of the way the big boys operate - I use VATSIM as well from both sides of the scope and strive to operate in as close a simulation of the real world as possible. Before VATSIM I wouldn't have known about SIDS, STARS, SLPs, airways and all that nonsense and I like to think I know my way around an RVA when I'm playing at being an approach controller :-)