Buying a used e70 35d..

[MaverichX5E70]

Hey guys, I'm agressively looking for a 35d X5 and have come across a few, and would appreciate some opinions.

First off, what is the most important thing when looking at a used 35d?

I found one that is at a BMW dealer, was purchased at the dealer, has full maintenance history and has very low mileage. It's a 2013 with 35,000 miles on the clock.
It's a nice SAV, it has comfort seats, panoramic moon roof, 360 cam, nav, hifi stereo.
I don't mind the color combo of space gray/black but white/black was my first choice.
It doesn't have Sport package or wider flares, but I plan to retro fit and put 20" or 21" wheels on it. It also doesn't have comfort access.

I think I can get the SAV at a decent price, given the time of year and also I think because it's not the most desirable package..

My question is, should I go with a SAV with low milegae and history over something with perhaps higher mileage, questionable history but with all the bells and whistles? I mean, this one I am looking at isn't terrible, it's just not exactly what I want.. But if the price is right, I can retro fit or live with what it doesn't have... I think.

What would you do, and why? If the vehicles are the same year and price, and one is closer to base with a 1/3 of the mileage as the other that is fully loaded with questionable history (traded at a non-BMW dealer so all they would have is the carproof), which would you choose?

This is the option sheet for the one I am looking at:
Model X5 35D XDRIVE (USA)
Steering LL Doors 5
Engine M57Y Displacement 3.00
Power 210
Drive ALLR Transmission AUT
Colour SPACEGRAU METALLIC (A52)
Upholstery LEDER NEVADA/SCHWARZ (LUSW)
Prod. Date 2013-05-07
Vehicle options

S1CAA Selection of COP relevant vehicles
S212A Equipment, brake syst. country-specific
S245A Steering wheel column adjustment,electr.
S248A Steering wheel heater
S2DEA BMW LA wheel Star Spoke
334 S302A Alarm system
S316A automatic trunk lid mechanism
S319A Integrated universal remote control
S386A Roof railing
S3AHA Backup camera and Top View
S402A Electric panoramic roof
S423A Floor mats, velours
S430A Interior/outside mirror with auto dip
S431A Interior mirror with automatic-dip
S441A Smoker package
S456A Comfort seat with memory
S488A Lumbar support, driver and passenger
S494A Seat heating driver/passenger
S4ABA Fine wood trim burr walnut
S4NAA Interior mirror with digital compass
S502A Headlight cleaning system
S508A Park Distance Control (PDC)
S521A Rain sensor
S522A Xenon Light
S524A Adaptive Headlights
S534A Automatic air conditioning
S544A Cruise control with brake function
S548A Kilometer-calibrated speedometer
S575A Supplementary 12V sockets
S609A Navigation system Professional
S620A Voice control
S639A Preparation f mobile phone cpl. USA/CDN
S645A BMW US Radio
S655A Satellite tuner
S677A HiFi System Professional DSP
S697A Area-Code 1 for DVD
S6AAA BMW TeleServices
S6ABA Control for Teleservices
S6FLA USB/Audio interface
S6VCA Control for Combox
S761A Individual sunshade glazing
S823A Hot-climate version
S853A Language version English
S876A Radio frequency 315 MHz
S8KCA Dummy-SALAPA
S8S4A Decoding variable light distribution
S8SCA Telematics access request,country-spec.
S8SLA Trailer coupling preparation
S8SMA Car ident. number visible from outside

The most important option for me was the comfort seats with my bad back.. But is there anything else missing here that you couldn't live without that you're glad you have on your X5 now ?