Disagree about Pegi being the best because some games in Europe have been censored to avoid getting an 18 in order to get a 16. Even though its only 2 years apart, devs still feel the need to do that. Granted, not many games have been censored to get a 16 instead of an 18 unlike tons of games getting censored to get a T instead of an M. Imo the Esrb should just get rid of the AO rating and just ban pornographic games from consoles. Getting rid of the M rating wouldnt make any sense. As you said, its only a year apart from the AO rating. Not only that, the M rating has been around for over 20 years. And its on thousands of games. Seeing it gone would kinda suck.
Btw, when I say pornographic games. Im not talking about ecchi games like Sakura Succubus or Hentai vs Evil. Im talking about games like Rapelay or something like that.