[acjohnson55]

I've gone full BEM on a recent project of mine, and it's been a godsend. Name our block elements by function, take advantage of SASS's abbreviated BEM syntax, reuse actual presentation styles with mixins, and use helpers within our templates to vastly minimize BEM's noisiness in the markup we work with. The modifiers are also great for capturing variations.

AM strikes me as clever, but I can't see it replacing class-based styling. At best, with some extensions, it might be a slightly more abbreviated way to write BEM, but decent tooling can do that for you anyway.