Ok, just to close the loop - I have ACC.
I finally installed the new ACC DSC unit. With the E70 X5d, do yourself a favor and rotate the upper intake pipe to the other side of the oil cap. You can pull the DSC out there while holding the hydraulic pipes aside. Also, drain the brake fluid from the master cylinder reservoir or it will completely drain when you remove the pipes from the DSC unit. I did not pull out the entire DSC bracket- just removed the two bolts on the bottom of the bracket that secure the DSC unit to the bracket. I tried vacuum bleeding, but I'm not a fan. It draws too much air through the caliper vents and you can't gauge the amount of air in the line. I wound up having a friend pump the pedal while I manned the caliper vent, then activated the abs pump bleed function a couple times at each wheel. The brakes feel great. I don't think the last shop did a very good job, but the old fluid was clear.
ACC is great. Very happy with it.
My active steering project is progressing. The only errors left are from the EMF (parking brake). It complains about the DSC interface after I code $217 for AFS. I've read the EMF can be finicky and there is a workshop mode. I will have to play around some more. Anybody have any hints?
Also, does anyone know if the ACC radar must be calibrated for best performance, or does it only need calibration if it complains?
A big thank you to everybody in this thread for your tips and hints!