I use the sims to work on my stick movement and orientation mostly. I've found that the landing on the sim is not that well simulated as it is in real world. For one, your field of view is not the same. Also, the wind simulation in G4 is constant. You set it at 9mph at a certain heading, it's ALWAYS 9mph in that heading. In the real world, that doesn't happen.

At my field, our wind has turbulence and the plane will always act accordingly (Jittery on landings), so you constantly need to adjust with ailerons and rudder. Here is a little video of me messing around sorry i've only been flying couple months so still learning but you can see in the end, how the plane reacts to the wind... http://www.youtube.com/watch?v=VpXWc0pAayI

I practiced my lands on G4, then I showed up at the field and it was not the same experience.

what the G4 DID help me with was orientation. When I was coming in for landings at the field, I knew that the controls reverse, G4 helped me a lot in that regard. I practice my orientations on the G4 a lot and now hardly think about what move to do, it just comes naturally.