You never feel the AD "engage" or "kick-in", it is always on, always dampening the road.

When you push the "sport" button then everything tightens up a little more. You will feel a little more of the road, but the car will corner like a significantly smaller, more nimble car. But even with sport engaged, you will not feel adaptive drive doing it's thing. You won't feel/hear anything engaging or starting.

AD is the single best option on the X5 and it is a strange move for BMW to only allow "priority-1" orders to add it. In other words, dealers ordering spec cars for their lots can not add AD to the car, therefore there are almost no X5s with AD for people to test drive.

You have been fortunate to be able to find a used X5 with AD to drive. You have felt the benefits. It is expensive but worth it. Add it to your order, you won't be disappointed.

Good luck.

And I would also consider Active Steering. Makes the car easier to maneuver at low speeds/parking, yet maintains the taught feel at highway speeds. Has been one of my favorite options (after AD). Turns the wheels lock-to-lock with like 1/2 turn of the steering wheel. Amazing. I can't remember the last time I had to turn the wheel hand-over-hand. just my 2c.