Just to add my own experience, I have a friend who had the Elgato Link and it died. He decided to give a $15 amazon one a try and he said it works "just as good" as the Elgato one. So I then bought my own $15 one (having never used Elgato before) and I can also say that it does the job.

I don't know how to further qualify it, you expect it to convert HDMI into USB and it does it. The resulting quality is amazing. So it performs its function.