I do... I keep it out in the wood shed, and we've got our wood splitter mounted to the top of it.
Got it as a hand-me-down when my father in-law dropped it off as one of his woodshop buddies didn't want/need it it any more.
Its light, easy to move around, and I love the way the whole bench top acts as a vise... I've got a 2x12" here that's longer than the bench is wide, onto which I've bolted a 2x4" on one side, which I then clamp into the bench top. Makes the bench extra-wide when needed.
I wouldn't consider the Workmate suitable for doing much hammering on, but for a quick bench to haul around and mount power tools on, they're ideal.