I have 2002 and am in the process of getting 2004.
I think it is awesome as a bit of fun and is great for practice etc.
The interactive lessons are ok but based on FAA regs etc and can be a little annoying.
I havent really used any other SIM yet and am sure there are some out there that are better for real training which hopefully someone will clarify.
You can download hundreds of aircraft and install them and use them in flight - the scenery is awesome however make sure you have a nice high powered graphics card as this will make it even better.
You can also fly online with other pilots but you need a fast connection.
PM me if you have any other questions as I have used it quite a bit for a number of years.
Regards
Lee