very very very much so.
i honestly wasn't expecting them to offer as much of a gain over singles as they do. the power transfer when climbing and stopping approach that of a clipless setup once dialed in (it took two or three days of riding to get the primary/secondary strap balance squared away) without needing overtightening.
they're great, especially when combined with the mks cleat-as-a-platform i have going on.
my gf now has a set w/ two singles too; i'm considering buying a few more pair for our beaters.