When it comes to choosing clock time there's 2 ways you can look at it
1 - The way you guys are used to, playing 5 or 6 min Q's playing the game as fast as you can and the only strategy involved is within playcalling.
2 - Playing with 8-9 mins with 15 ACC clock which then factors in the management of the clock, proper use of your timeouts and allows players to take a different approach to their game outside of the only one available in option one, which is just score more points. You can't play option one and then take an approach of churning out 1st downs and keeping the other teams offence on the bench or else you'll have some really short games.
So really, it's up to the community to decide if they want that added element of strategy in game management or not. When you play the 5-6 mins straight up, you know you got a 30min or so real time game. With a 8min 15ACC you can be anywhere from 25-40 mins in length because of the added strategy players can employ.
That's what it boils down to when you are choosing your time settings. When it comes to TGT I have no choice but to balance the amount of plays with total points as best I can because of how statistics are tied in with player progression, but in pick up games that's not required, but still having said that those are the elements you are picking between.
As for AM vs AP. It's clear as day that AM makes ratings mean less because players will play beyond them, which I find stupid and pointless personally, but again that's just me. Since sliders are an option, pretty much anything the community feels is not working can be adjusted which should be the approach.
/shrug