or... arguably kept the 'same' battery life as previous devices, but added more battery draining 'stuff'.
I had one, and returned it, partially for battery life. I'm doing a lot of development (intellij/phpstorm/virtualbox/etc). The battery life wasn't bad - at heavy use, I could get perhaps 6 hours of 'real' usage, but... It was $3700, which was a bit much for my blood given the battery shortcomings (and a few other reasons). But mostly price/performance relative to my workload. For $1200/less I got an approximately similar 2015 model with more battery, and a slightly heavier weight.
A lot of people feel it ... isn't the same.