Mutants and Masterminds rpg

Hey guys this isn't about a computer game but a table top rpg.

I found this game the other day and was wondering if any of you had any experience with it. Wondering what difficulty level it has and what age group minimum you might think it would require.

Also, do you know of any play by mail games?

Seems like a pretty cool game with lots of expansions.

Thanks for any info...

I've played it and enjoyed it. For some reason I find it easier to play in character with M&M as opposed to D&D. Can't really speak to the age appropriateness, but in terms of difficulty it's no worse than 3.5 D&D.