Definitely a breath of fresh air! I would buy it of course as I am constantly testing new admin approaches for/ within WordPress. There are already a lot of other approaches out there - look at WordPress.org repo or marketplaces like CodeCanyon...

Stuff is "only" likely to break if plugin and/ or theme developers make their stuff not compliant with the core UI and API. I have no problem if stuff breaks, then we have the chance to tell those devs what's up and that they should become active in using the core UI & API. That might sound like a bit more work but in the end a win-win for all parties involved.

Really can't wait for this plugin mentioned above!!! :-)