Battery life seems not like a surprise. Isn't Apple only selling 2015 MacBooks without a discrete GPU? So you basically only have Intel Graphics in there which would mean a charge lasts much longer if it doesn't need to drive an NVidia or AMD card as well.

I'm inclined not to believe the 15 hour claim. I've had the 2015 MBP since it came out and get maybe 4-5 hours of battery life doing non-heavy web development nowadays. After I newly bought it I got maybe around 7 hours at most. With integrated graphics only of course - with the dedicated GPU active I get around 3 hours or so only.

Are you using Chrome or Electron apps? Chrome rinses mine in about 3-4 hours, whereas Safari lasts all day.

Same here. I didn't believe my friend when he told me it was Chrome and, for some reason, I didn't believe the battery meter that kept telling me that Chrome was using significant power. Switched to Safari and now my battery lasts all day. If I could get Slack to play nice I think I'd have over a day of charge (1 day meaning a 12-16 hour working day, not 24 hours).

I'm not inflating my claim, but it's possible that I use really efficient apps most of the time compared to the average user. I am also not watching movies or YouTube or listening to music. Just writing code in a very efficient editor (emacs), and doing very little web browsing.

Also perhaps they improved their batteries in the most recent iteration? Just guessing because your experience is definitely different than mine.

I needed to replace my 2010 macbook air and after much consideration I ordered a maxed-out (excepting SSD) 2015 mbp last week.

Buying previous generation hardware feels weird, I hope I don't regret this decision.