I have three, one running, it seems to be about as strong as a Golden Bee if you prop it right -- I don't know why Andrew's experience isn't as good, but then I haven't been really scientific in my research.
If my three examples are anything to go by, the quality isn't as good. I've heard that they have a rep for breaking cranks -- but that's just hear-say.
My engine, without tank but with Andrew's maligned spring starter, weighs almost exactly the same as a Golden Bee with tank. So you do have to take the weight into account, but aside from that it seems a nice all-around engine.