This is the god's honest truth. The Touch Bar is the most useless feature on a laptop you will ever come across. Yes, it seems novel, but in reality it's useless and you'll end up using it 3 maybe 4 times and then you wont. The battery life is negligible and you likely wouldn't notice a difference. The newer one get slightly better battery life compared to the older but that depends on what task you're doing as well as many other factors. The newer device has a much lower TDP than the older one, TDP refers to the power consuption to processing power ratio. Lower TDP = Better battery life.