Hi Wild Blue,
Here's my understanding of the various options:
1. Dynamic Damper Control monitors and automatically adjusts the shock absorbers – see more here: http://www.bmw.com/com/en/newvehicle...trol.html#more
2. Adaptive Drive combines DDC and Variable Damper Control to decrease body roll, more here: http://www.bmw.com/com/en/insights/t...ive_drive.html
3. Integral Active Steering (http://www.bmw.com/com/en/newvehicle...ring.html#more
) means four-wheel steering, that is, the rear wheels are used for steering and are able to turn up to something like 3 degrees. At low speeds, it reduces the turning circle (= easier steering in the city), while on the highway it increases cornering response. It's a separate option IMHO and is NOT part of DDC or Adaptive Drive.
My GT has Adaptive Drive but not Active Steering. I haven't tried the latter, but don't currently miss it. AD/DDC I probably would miss, and recommend specifying on your options sheet. My 2 cents.