Long time Audi fan.. Long time owner (not a Q7, but friends/neighbors do)
* The reliability issue is false.. It will be just as reliable as any other car.
* Repair costs being high is false.. Most of the parts are stock VW parts.
Find a quality 3rd party mechanic and you'll pay about the same as any foreign car***.
2017 is when they 'redesigned' the Q7 (and other models) so you get the nicer dash and options like the 'Virtual Cockpit' (Digital Dash). The front seats give you the classic Audi Interior feel. The 2nd row is comfortable for 2 adults... My wife never liked the Q7 because the 3rd row is small (and we have tall kids).
You'd be hard-pressed to find a NICER interior than the Q7. Slap some iPads/Tablets into the kids hands and you'll have a great road-trip car (as long as you don't need bigger kids in the 3rd row 🙂 )
*** Things like breaks/rotors are larger on the S/RS Audi models so you will pay $$$ for the sporty options.