I have the new Marvel Rpg and been reading it the last few days. I thinks its "OK", not great, not bad.
Being Diceless there is some "quirks " with the system.
Like the fact Captain America can physically hit AND HURT the Hulk. Hit him? Sure, HURT HIM? I wouldn't think so.
The game does a good job of capturing the "feel" of a comic book and promoting a story in a comic book way.
The stones idea I don't care for in combat(see afore mentioned Cap/Hulk thing). People who shouldn't be able to hurt somebody else can, some people CAN'T hurt others-EVER, due to a high Def and having enough stones so the other, even if they put all their stones in offense, can't match them(Example Cyclops can NEVER hit Cap unless Cap wants him too, or he ambushes him or something). They can't even get "lucky"-since no dice equals no randomness.
It makes the Durability score way, way too important(balanced somewhat by the fact this ability costs 3x as much as others), along with Toughness skill.
I would give it a 5.5 on a scale of 10. Not the worst Superhero rpg I have seen by far, but would not be my first choice either.