Another tiny update here. After installing the D2's rear, I felt two things going on. One was there was more weight on the front. Quite noticeable. Other thing was rear felt a little jittery, underdamped. These are related of course.
The first thing caused what seemed to be the previous nice neutral to oversteer balance to shift to more of a pronounced feeling of weight shifting onto outside front tire in a corner, back stepping out quickly and too much. Felt like a bit too much rear bar IOW. The jittery rear made this transition happen too fast.
So what I did was get a front UUC bar, check the thread on UUC bars for 335xi, post #48:
http://www.e90post.com/forums/showthread.php?t=532951
Then I cranked the rear konis up to 1 full turn off soft, they had been at 1/2. Everything is nailed down really nicely at both ends now. Not harsh, just firm and supple with very little roll. Front bar is a necessity IMHO, you shouldn't do a big rear bar alone.
However! Now that I can get more aggressive with the car it is bottoming and scraping the nose (!) on some bumps. This may push me into swapping out the front Eibachs for some D6's. If I do this I will also go to OEM ZSP bump stops, which are a little taller than the e36 M3 stops I have in now. This would be an experiment. Winter is coming fast here and I do not want to be nose heavy and bottoming out.
So yeah car is really handling well now, well enough that I can go out and mess it up.
BTW I cannot imagine going through this without having some adjustment capability in the shocks. I enjoy this sort of thing I can see how it might drive other people crazy. Keep in mind no one really knows yet how to do the XI right it seems. A lot of issues form the heavier front end, the taller front struts, an the awful OEM starting point make this a challenge.
edit: BTW I used the procedure developed by critical05 (I think), where you do not have to remove the shocks completely. You take out the carpet in the trunk, jack up the rear and remove wheels, undo the mount, drop it down, remove stops etc off shaft of the shock, and adjust it on the car. Was pretty easy. Biggest pain is that trunk area carpet.