Byrna, I think as others have said, FS is OK when it comes to steady-state air movement such as constant steady wind, but is very unrealistic when it comes to updrafts, downdrafts, gusty and turbulent conditions.
I still found it useful though when I recently started my PPL. Definitely helped for navigation, procedures etc. I also found I had a pretty good "sight picture" straight away when it came to the approach phase of landings. It didn't really help in that phase of landing from 100ft down, which is more about feel and control.
In defence of the FS series, it has to model a vast range of aircraft and covers the whole world with respect to scenery, so I can forgive its flaws.
I've tried all the sims, x-plane is fantastic, but too sparse for my tastes. Flight Unlimited was great at the time, but had very limited plane-sets and scenery areas. My all-round favourite is IL2-Forgotten Battles, which not only has a great feel for the experience of flying, especially at low level, but also allows you to shoot stuff
- Michael