getting back to the sim issue....before starting my ppl this june I spent a lot of time playing around on a sim. it helped me to form patterns in my head about the physics of flight - effects of controls etc - so when it came to start doing the real thing, I had a pretty good idea about what was going on.
obviously you don't get the seat of the pants feel, or the occasional pinball in a washing machine turbulence effect, but it definately sped things up for me. now I'm 10 hours into 'reality' and using the sim to practice procedures in the flight training manual and checklist run throughs.
long story short - it's saved me a lot of money.
and as already pointed out, flying in FS2004, even with a full yoke / throttle / rudder setup, is actually harder than the real thing. and for the first 2 hours I drove my instructor nuts with over-reliance on instrumentation!