FfH is better. That's not a slight against Faerun (which is decent and fun enough) but the depth of FfH is immense. As a result, it feels like a different game while Faerun still feels like Civ5 with some fantasy-flavoured changes.
Even as a big Civ5 fan (I like Civ5 BNW more than Civ4 BtS), Civ4 is still better for mods and total conversions (also see Dune Wars and Planetfall). If you like mods, snapping up Civ4 for cheap is definitely worth it.
Thanks, i might do that then. Honestly I'm not really interested in playing Civ 4 (as I really feel like Civ 5 satisifies my civilization experience but for a good fantasy mod I like the sound of it.)
Do you recommend Fall from Heaven 1 or 2? I guess 2 is the better one, it seems newer and more dynamic?