Where do you live? Big temperature swings are tough on exterior paint, and keeping it on a heavy wear area is even harder.
I would skip the Behr. BenMoore has a epoxy reinforced porch and floor latex that I like, mainly because it's easy to touch up .
Up here in the frozen Tundra (MN) I advise people to use a penetrating semi solid on exterior decks. A full coat that sits on the surface is bound for failure.