I was an avid FS9 user for a long time. I've only just jumped ship to FSX because developers are moving away it.
FS9 can't cope with the complexity of add-ons nowadays anyway (lot's of CTDs and Out of memory messages) from what i've seen on other forums
etc.
Glad i did though in all fairness, plus it's an excuse to invest in a better machine to run it on!