While I have some problems with MCSR's "My Strength" campaign (I think that it, unfortunately, plays on traditional male masculinity--i.e. 'men must be strong', and the images used in the various media of the campaign reinforce traditional male masculinity as well), I think that Stoltenberg's basic take on the ways that feminism can help men is right on. Feminism can help men realize that traditional conceptions of masculinity can be harmful to men. In "Why I Stopped Trying to Be a Real Man" he says:
As I watched guys trying to prove their fantasy of manhood--by doing dirt to women, making fun of queers, putting down people of other religions and races--I realized they were doing something really negative to me too, because their fear and hatred of everything "nonmanly" was killing off something in me that I valued.
That's why I feel a connection to feminism. I want a humanity that is not measured against the cult of masculinity. I want a selfhood that does not reject fine parts of myself just because they are not "manly." I want courage to confront the things men have done in the world that are damaging to women and that are also leaving no safe space for the self I hope to be.
Go check out Men Can Stop Rape. Some of Stoltenberg's writings can be found here.