Depends on the person and really the AAU program you align with. I enjoy AAU basketball for the fact it allows you to evaluate how players stack up when facing against peers they'll be competing against in College. Also think the situation you are in as a player dictates what's best for your development. If you lack ball handling/shooting ability and are a perimeter player, you are better off spending a lot of time in the gym and working out. If you are injured, it's something I'd recommend no matter what level of college ball you think that you'll play. Not going to help if you are injured if you go out and miss every shot or look terrible against ball pressure because you can't use both hands (Adou had a wrist injury for example).
Each to their own but the benefit of big time AAU isn't in winning, it's in being seen in front of coaching staffs and competing against top competition. Thiero and Porter had advantage of their family knowing big time coaches, and having played, so that also needs to be taken into account. Then they followed up their off court development by having monster HS careers/leading team to deep runs which brought more attention to them/their game.