I don't like this line at all. IMO, you should shove, but the line you chose allows your opponent to find a fold on bad boards, and stay in on favorable boards.
The only reason I can think of to flat is if your opponent has an extremely high UTG PFR percentage and/or a very high C-bet statistic and rarely folds post after that sort of action. Otherwise you're better off shoving, because you likely don't have much fold equity, which is the situation that you want to end up with when you AA (no fold equity, that is.) I mean you're giving them better than 2:1 on a call, I don't think they're folding very often preflop, and the value you lose when they do is less than the value of when they get there against you and you get it in bad.
I'd say this, that flatting can be OK but not if you're going to simply donk bet without a solid read. That's not generally a profitable move. If you're going to flat, I'd think that c/r-all in is a better line against an opponent with a high C-Bet
