I used FS98 and FS2000 until I started my PPL in real life. I no longer use them. I have moved onto more serious sims such as precision simluator 744 and flitepro.
However, FS98/FS2000 did give me an insight to flying and helped with much of the terminology that one is introduced to during a PPL (helped me with communcation with atc in particular).
I tried flying a circuit in the Cessna on FS2000 after my first few flying lessons. There was no comparison. To me FS2000 should be used strictly for fun.