What are the benefits of theming using this module compared to "ui_patterns" and "ui_suite"?

That's a great suggestion. I'm working on my BoF for DrupalCon, so I would have that info soon.

The short answer, is that we're skipping the rendering of the fields (along with the fields formatters), or any special layout module.
Instead we have full control over what's printed on the page. The node acts as a content repository, and we craft the output with re-usable render arrays.

More info to come :)

It sounds promising, I'll try to learn this technique.

Looking forward to more info :)

Here it is. Not a direct comparison, but should give an idea of how different it is (very).

https://www.gizra.com/blog/pevb-video/