I can't seem to find any decent discussion on some of the AI traffic addons for FSX. Most of what I find is quite outdated.
I've got an i7 860, 8GB DDR3 1600, and a GTX 470, and I get about 35 FPS at major airports (with jetways, no AI, including ground vehicles) and 50+ away from airports, display settings all on ultra high. I haven't tweaked a line in FSX.cfg though - so that could change.
I gave World of AI a shot - but I saw planes landing on the threshold and turning off the runway at the second taxiway, plus my frames went down to ~10. I'd love something with a lower impact on FPS.
I don't care much about real life schedules, but its a perk if everything else is the same. I just want some life in the sim. I don't care too much about the cost either, so long as it is good. GA would be a bonus, but I don't mind making my own schedules for the GA airports I usually fly in and out of.