... But then I did purely for testing purposes once ordered this box (which by the way is very compact in its original and only in the picture looks so great). For the Mac there is a compatible, current drivers easily be found on the website of DisplayLink. Since this product works apparently after DisplayLink standard, as do various devices from different manufacturers can be assumed that the latest drivers are available any longer available. After installing the driver: Plugging, Goes. Namely, easily and very reliable. Even after restart or hibernate the additional screen on again with a correct (or even off), so that one fades out completely, that this "only" is connected via USB.
The 2010 MacBook has only USB 2.0, as USB 3.0 but is backward compatible, I opted for this variant in order to be prepared for the future. The picture runs very smoothly even over USB 2.0 with intermediate USB hub and USB extension. YouTube videos are not in it, local QuickTime videos go but smoothly, liquid and fast scrolling, and smooth working but definitely.
Conclusion:
That my third screen via USB and is not connected to the "real" video card, only falls into a situation: If I have due to the completely judder display forgotten once again that the screen hangs "only" USB 2.0 and try a YouTube -Video play it.
I am thrilled to clear recommendation!