I remember them now a little (been away from Oblivion for a good long while). I kind of like Natural Weather's vivid color - especially when the sun is out late in the day - everything's really vibrant and bathed in sunlight. AWS was more subdued. Never tried EW.
Does this work well enough with http://www.tesnexus.com/downloads/file.php?id=8711 by Deathless Aphrodite? Seems like it would. That mod is freakin great - the lightning strikes are not only visible, but light up the area around you if you're close enough! I love it!
Yes, it is compatible.
EDIT: I did have a quick look at the stormy weather sounds last night - all the exterior weather have 4 sounds attached, which is OK, but most of the interior weathers have 10, which is overkill, so I'll remove some of them. I'm putting off checking them out in game because I don't want to stop listening to some rather good music I've just picked up.

EDIT 2: Turns out we had 12 duplicate sounds, and for those 10 sound weathers, 6 of them were these duplicates, so you'd get 8 of the same type of sound (thunder or thunderdistant, both are taken from folders of similar sounding files) being played at the same time. No wonder they sounded a bit crazy. :blink: I've removed those duplicates, and I'm going to add the right sound types to the weathers, and then check them out it game.
EDIT 3: Hoo Boy. More than half of the weathers' sounds were incorrectly classified, and some weathers had mismatched interior sounds, and there were 2 duplicate NoWindows weathers due to these mismatches. I'm glad that Arthmoor brought up the issue with that stormy weather, else I may never have noticed this. It's fixed now though.
Next on the list is HDR nerfing and detection of alternate fast travel systems, and then it's just making sure all my changes work. If anyone's got any really ugly weathers they want fixed for 0.9.9.5, post the FormID and what you think is wrong with it, and I'll take a look.