I didn't bother with the extra trees in Balmora, that looked silly IMO. I picked all the others though (and the lore friendly option one). I'll grab a screenshot later of my settings. Grass option is "colourful" but I don't seem to have as much grass as in some other people's screenshots - perhaps I deselected "lush grass" or some such thinking about it, because I know in Oblivion the grass makes finding lootable bodies etc a nightmare to find.
I've got the shaders that max settings comes with still, I haven't disabled SSAO yet, but it's driving me mad because it makes me feel like I've had too much to drink - it doesn't appear to be that well implemented as I'll be staring at a body in the distance and it just won't focus.
So, yes, I'll disable SSAO and that should sort the FPS out. It's perfectly playable as it is, doesn't appear to drop below about 35fps but I think that reducing "draw distance" to about 9 or 10 cells from 11 may help as well, I'll report back.
By the way, DON'T pick the "naked" option on the better bodies. I did this thinking it'd be good for realism and had a bit of a shock when I looted the tax collector bloke's body in Seyda Neen.