It's a lot better than a TripleHead (though obviously a lot more expensive)
A lot of graphics cards are constrained to a 4k horizontal resolution limit, which means that with a TripleHead you can only achieve 3x 1280x720 displays. However, with the QuadHead2Go in a 2x2 configuration, you can achieve 4x 1920x1080, since they all fit within the 4k frame.