Everyone talks about Websockets for pushing real time data to the browser. This article highlights some of its drawbacks. I use Server Sent Events (SSE) instead. A lot of the problems the author of the article faced are solved with SSE. Also, SSE scales way better than polling all the time.
I didn't see anything in the article about battery capacity or the density. This (with the other info in the article) would tell us if this is groundbreaking or not.