I am an Audi loyalist, I’ve had no issues at all with them over the years other than extremely minor things. It will be under warranty for a while, how long are you planning to keep it?
Maintenance cost: I just replaced the tires on my S8, that was painful. Low profiles are always pricy. I bent a rim on a pothole once, I remember that being fairly expensive too. If the engine ever needs work, I don’t even want to see that bill. So yeah, I think this particular model is costlier to maintain.
As far as a family sedan, that depends on how much room you like in the back. I had an A8L for a while, and I loved that car for teenagers who needed more leg room. My S8 is pretty roomy too. If you have kids in car seats, you might want to look at the A8 or A8L.
One of my partners drives an A7, that is also a really nice vehicle.