Here's some of my observations on the lag with EE.
EE is experiencing bugs that were repaired back in old school NWN. Like full metallic clothing glitches, shaking overhead text at certain camera angles, vanishing text blocks, snow lag, ect. All were worked out, but maybe going back into the game to rework it undid some of those repairs. I am probably using the wrong terminology, be kind it's 5 am.
The lag for me cut down significantly if I keep my camera scope tight instead of zoomed all the way out. If it's snowing, i get a lot of lag. I have to have all the depth settings and advanced video settings turned off, but i am finding I can play around with the tradition settings and not have too much impact. If it's not snowing, i can have the new settings on and the old ones turned down and not experience lag.
I really think this is a balancing issue that will be resolved if we stick to it and work out the problems as a community rather than let our frustrations get the better of us. it's just lag. We're better than lag - we can always turn down the settings until it's resolved.