Badly. We feel very badly about them. In my opinion there is no deal good enough to be worth buying them right now.
They were not very durable, and now they're not being made anymore, so if/when they break, good luck finding parts.
They require modifying your boots, as others stated, which is a real PITA.
They're not actually any safer than tech bindings, so you're lugging around more fragile parts for no real gains in that arena.
They don't ski much better than lighter, cheaper, and more durable tech bindings.
I wouldn't pay to have Beasts mounted on a pair of skis, even if they were free, right now in 2021. I'm glad they worked well for some people. That said, there's a very good reason Dynafit discontinued them so quickly.