On my black-interior P85, the tan pillar color also struck me the same way. On my black-interior Mercedes S550, the pillars between its doors are black while its headliner and windshield pillars are tan.
The S550 black center pillars look much better especially against the black retracted shoulder belts. Looking at both cars in my garage side-by-side it's obvious the P85 would look better that way.
Another difference in details that struck me were the lack of front seat storage compartments that the Mercedes has - sunglasses, umbrella, first-aid kit, door pockets, double-deck armrest compartments.
I've had several Mercedes and their experience and continuing improvement with all these little aesthetic and "creature comfort" details are subtle but appreciated as you spend more time in the car. In the end, the overall technology of Tesla trumps all these details, but Mercedes does deserve credit for "sweating the details" and Tesla would be well-advised to take notice of this little stuff.