I have to admit, my initial thoughts about REX E was "so what". Screen shots were not that convincing. But since it was a free download on top of my current version of REX, I gave it a spin.
I must say that the cloud textures seem more realistic, softer in texure, and some of the early morning lighting, haze effects are quite beautiful when you run the weather engine. They turned the volume up on the thunder which is unfortunate because the original thunder sounds seemed more realistic, distant - to me ast least. No FPS hits that I can tell in early flights. Add Shade, and the expereince is quite lovely.