I chat with models not associated with a particular website, so pretty much all my privates are on Skype.
I did try Discord once, but I didn't really notice any difference in video quality. What I don't like about Discord is that I can't find any way to adjust the size of the video... Unlike Skype, it doesn't seem to scale with the window size, so even if I have the Discord window maximized, the video chat takes up less than half of the screen vertically. With Skype, I can make the video appear as small or as large as I want by resizing the Skype window.