Reported.
Anyone can measure Surface 3's power consumption, it's not something forbidden like the Mullins reference platform AMD sent to reviewers to make it look competitive inside a 11.6'' thick chassis that doesn't resemble any typical 7-8'' tablet Bay Trail-T product. They obviously had to hide the outrageous power numbers and put a giant chassis to allow it to sustain Turbo speeds even though they knew it would fail miserably to deliver this kind of performance inside a real small tablet, you know, similar to your Core M accusations. OEMs obviously knew that, hence why it almost didn't make it to the market. Do you really think they couldn't have launched such a product at higher prices if it really outclassed BT like that? Surface 3 at $500 is the proof they could.
Ps: Braswell completely smokes your precious Kabini in perf/watt, even AMD-biased Hardware.fr aknowledges that:
http://www.hardware.fr/articles/imprimer/936/