You can search around the forum for that, it's been discussed at length:
In theory, you'll have better performance and security.
In practice, however, at least for the time being, you will not notice a thing. The real difference is software support: as you've seen with gnome-screenshot there are other programs that don't support or work well with Wayland, and you'll need to jump through hoops (or use different tools).
In this forum, half the issues are caused by Flatpaks and/or Wayland. Two technologies that were full of promises but are still very lacking in a lot of aspects.