I've just purchased a Duo clone and spent today setting it up, maybe I was expecting way too much as I'd read nothing but good about the Duo and therefore clones but I've been totally underwhelmed by it.
Why? you may ask, well the fan in the thing my son describes as a "like a truck" it is loud, way too load for a living room box, I've found the remote on it to be very directional, point it at the box else nothing. When zapping through channels you sometimes end up with a black screen, restart the box and the channel is there, I've read up on this and this apparently is a security issue and exhibits itself on the clone more so than on an original. Also for me, the TV that the Duo doesn't have HDMI so I connected it via SCART set to RGB which results in great PQ but the picture is heavily tinged green. Got around this by connecting the box via component in the end.
The box itself is humongous, my wife initially asked me why I'd brought the old video out of storage.
Apart from that it's not a bad box but my dm800se clone as far as I'm concerned has better build quality. looks nice and cute and does what it says on the tin.
Don't let me put you off though as the Duo is still a great box and I think in all honesty I just had too high expectations.