Probably neither, I would keep looking.

AD gets great reviews. I am sure it works. But it is another thing to break and then fix, to me. If I needed the improved cornering capability then I would rethink my need for an X5.

Comfort seats are a must, I'll never go back. Massage and ventilation would be a negative, for reasons above.

CPO would be a must for me here, since that is the only BMW extended warranty available.

Upgraded stereo wouldn't matter to me, my stereos have all been better than my ears are.

Never thought comfort access would matter, then I got it in a package. I liked it, but could live without it if all else on the vehicle was what I wanted.

Heated steering wheel would be a must have. We all have our weaknesses.

__________________
2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue