You also have to consider the spec of your
PC when deciding this. A lot of 'older' Pc's just don't have the capability to run FSX, some struggle to run FS9.
My specs for example are a
AMD Athlon 64 X2 4400 Dual Core, 2Gb of Kingston RAM, NVidia 7600GT 256mb, 120Gb Maxtor 7200rpm hard drive, Windoews
XP Sp2 and 500W PSU. They are the main things and I run FS9 at a solid 25fps with all the sliders turned right up. The add ons I have are
GE Pro, Flight Environment,
FS Global,
FS Traffic 2005 plus 2 add on extension traffic packs and Active Sky.
Nearly all of the flying I do is airliner related , so most of the time I'm viewing nice scenery from 31000ft, which is why don't have any airport add ons at the moment. However, I have a huge box of them in the spare room that one day, may or may not get added on.
Keep smilin'