Opinions on this video quality?

The quality is amazing, no need to worry, but if you are going to vlog, I don't think a small GoPro would be the right choice since it's quite easy to lose considering the size and it's not meant to record hours worthof footage on it.

Try something like a Canon EOS Rebel T5i which is a good a bulky camera that would be very difficult to lose or misplace and it has anLCD screen which you can rotate so you can see how you look on camera, but if you are on a budget, forget about that camera since it's quite expensive.

What I suggest is:do your current vlogs with the GoPro then if your audience is growing and enjoying your content, try to invest on it by buying that camera or a similar one. Just a small tip.