The trick during the talk - that I made this site for - was that the grid is actually progressively enhanced with masonry where browsers support it, but no one in the audience would have known that had I not told them. It's the magic of progressive enhancement: everyone gets a fantastic experience, so they don't even consider if they are getting the "best" experience. They already are because everything works for them.
Using a CUBE exception, I added a masonry enhancement: The nice thing about this exception is yes, it slaps the masonry grid-template-rows value in, but also, aligns items to the start, so they at least only size vertically to the size of the content where masonry isn't available.
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