Used vu duo 2 for years and rock solid also use an ultimo 4k which is better..The Duo 2 is an old box now,but still a pretty good box years later and support is excellent. Maybe you should compare the hd51 to the newer solo4k which I think looks better than the hd51, has more image support and Kodi.You are also paying extra on the solo 4k for the FBC Twin tuners which you may not need. The Mutant is a very capable box but it looks cheap and the remote control is terrible so I feel vu are the better quality boxes but it's all down to budget and personal choice.