It’s good to know other ways to make animations. I see a big advantage with the method shown in your last video, and it is that is way simpler and fast. And it lets you see the model clean.
The method with armature is slow, as you said, and I don’t like to see the bones when I want to check the pose (even without x-ray, sometimes there is a tail of a bone standing out somewhere). Also I don’t like the way the fingers bend, with the deformation =/
Sometimes I’d want to separate more the arm from the body, and with the constraints it gets difficult.
But, at least, with this method, I can create a pose library, and that’s the best advantage, as I can create and save poses there, and later load them into keyframes, modifying only the body parts I want, so I can even combine some poses.
So I’m going to go for that method unless I make something very simple.