When I first started collecting as an adult I had the same question, quantity or quality? For me it was quantity but with good eye appeal. I don't think it has to be one or the other though. I like both high end and lower end as long as the aesthetics are there. Collecting sets is a little different as I like the overall look to be the same so will not go high grade (due to my limited budget). But for an individual card to stand on it's own high grade is fine.
As for AUT cards I usually prefer not to go for them as I would always want one without the "but" in the sentence about a great card. But it's different for everyone. I have owned AUT cards when it made sense. There isn't anything wrong with owning them as long as you acquired them as AUT on the front end.
