I wouldn't trade. The safety of for one. My wife and two children use the X 90+% of the time. The smaller cars may pass crash tests because of the cabin structure is rigid, but with the larger and heavier vehicle, more of the impact is dispersed thoughout the vehicle and not the passenger. ie. the crash test done between an old 90s S class Merc and the new Smart Car. The passenger cell was not crushed after the impact but the people would have surelly died due to the force of the impact transfered to their bodies.
These vehicles age so much better than do a "normal" car. A well kept German (even some Japanese) car will look better and more modern than many/most standard cars after just two years. Germans also keep the same basic body for about 7 or 8 years, so my first run 2003 E class looks almost identical to 2006 and very close to the 2009. When parked next to the new 2011 black cars, mine has more lustre and gloss than those do. I still get asked if it is new. I'm getting close to that look with the X, lots of work and upkeep though. The quality of interior in both my 2003 models are far far far superior to that af any sub $20K NEW car out there. Ride comfort, well, that goes without saying.

Someone mentioned they didn't think the X handles well!! I corner faster with that than I do with the E class and the E class will out corner my company cars (2006 Malibu, 2010 Impala, and 2010 Buick Lacross) by at least 15 mph on a loop coming on or getting off the interstate.

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'03 Black BMW E53 3.0i 110,000+ miles
'03 Black Mercedes-Benz W211 125,000+ miles
'13 White Mercedes-Benz W2o4 New