I agree, that animation like this, is the way to go, so ...
In the extension repo, we have a fully working V3 Spine version. Only thing not supported at this point is vertex animations. It still needs some TLC, especially the animation control is a bit rough around the edges.
The reason there hasn't been so much going on with the Spine API lately, is, that just running one animation, and then running another, very quickly is not enough. The API needs to be able to run ex leg animations, and blend them with different torso animation, while still providing full control of where the head is looking. We also need to add physics, be able to switch them on and off, and be able to blend forces applied into the animation.
Spine also has a Cocos2D API, but I do not think you will see any of the above features implemented any time soon.
Apparently Spriter just released v1.0, on which I congratulate them. They have had a rough ride. I do not know of any API they provide, but I know the file format is well documented, so I do not think it would be difficult to expand the file loader in our Spine API, to handle Spriter format. I can not promise when (or if ever) I get time to look into this.