Looks like it's pretty effective for something, though not necessarily easy on the hands. I love the idea of not having to stoop and dig. My knees and back give me fits, and I would like to see what stoopless weeding might be like -- especially for those (un)dandy-lions! ;)
It's not really a puller, but I like the circle hoe. It's just a hoe handle with a circular blade at the end; it's really good at getting weeds out unless they're the kinds that leave little nodules behind... it's a lot easier to use than a standard hoe.