Does anybody use GoAnimate or Vyond? What do you think of it?

To answer my question, no. You really shouldn't and here is why.

1. The animation is really bad. Research the animation principles. I understand most people aren't animators but that doesn't mean you should use bad animation in your courses. Most of the stuff I have seen have broken arms, the animation is really clunky, and the animation doesn't make any sense, not to mention the horrible drawings. In animation there is a reason why an animators makes a certain gestures and certain head movements.
2. Using this software is not creative. Please tell me how having a character standing there and just moving his lips is creative? Your course would be better and more rememberable if you just used bullets and pictures.
3. Good character animation is not symmetrical. All the characters stand really straight and are boring. Watch a Pixar or Disney animation. Characters are usually leaning a certain way, they have a line of action. If you turned off the audio you know what the character is thinking. This software is really meant for kids in high school. Sorry to have to tell you that.
4. The solution is to hire an artist. If you can't do that I suggest you study the Ken Burns method of creating a video with photos or shoot a video yourself. That is a lot more interesting than bad animation. Using bad animation over and over again is going to turn off your users. Animation is hard to do. Leave that up to the pros.