I thought the 2e upgrade of M&M was great for sure, I think the 3e update was fine, I'm not sure if it was strictly necessary but I did appreciate the DC versions with all of the heroes and villains.For my part, one of my favorite edition upgrades is Mutants and Masterminds 2E. It is superior to 1E in nearly every way (there is some hero point wonkiness), and the game got prettier and better supported in the 2E era, finally really replacing Champions for me and my supers gamers.
I thought the 2e upgrade of M&M was great for sure, I think the 3e update was fine, I'm not sure if it was strictly necessary but I did appreciate the DC versions with all of the heroes and villains.