Three Mobile broadband here, and don't use Skype video calls much, but it's always as good as a general webcam chat.
If you want to check out the quality of the call, the next time you're in one, click on the icon displayed for the person (the large icon), this will bring up loads of meaningless information. Feel free to screenshot this & post on this thread.
(ALT+PRN SCR will grab only the active window).