Regarding clouds specifically, would you guys say REX is an improvement over FEX, the same, or FEX has better cloud textures?
To answer your question I would suggest you browse some screenshts of FEX main site and then some screenshots over at REX.
IMOH REX beats FEX hands down.
It provides not just clouds but water, airport signs, runways, taxi, lightning and much more..
AND IT IS CHEAPER.
I have FEX already and I like it. The only thing I don't like is the clouds don't render at a distance. It looks extremely realistic at lower altitudes, but once you're above the clouds, the skies always look clear in the distance. I'll give REX a try and see if there is an improvement. From what you say about water, airport signs, lighting etc. I don't have anything to lose.