I dislike it, but respect and recognize the beauty of it when it's clicking. When it's off, it doesn't take much swing in the percentage of success at the rate that opponents shoot threes to get down double digit very quickly.
I just don't see the benefits from playing it anymore. It's tough to turn it into an elite defense (e.g., need time in the system, limited transfer opportunities, etc.). It's not like it allows the team to play without elite athletes, they still need them as we've seen. It doesn't allow them to play with shorter, smaller players, we've seen that. It occasionally completely befuddles other teams, but that's been limited to mostly poor teams with an occasional elite team (usually when the defense has the elite athletes needed and they could probably play a good M2M anyway).
If it allows them to dedicate other parts of practice to other things, well, I'm not sure what that it as the offense is a glorified pickup offense, the press only comes out when they're down double digits. I don't know. If an opponent is missing threes, then yeah, it works. I guess.