In my experience, Ubuntu 14.04 has pretty decent battery life on laptops as long as they use fairly standard chipsets and don't use fancy graphics switching bet

In my experience, Ubuntu 14.04 has pretty decent battery life on laptops as long as they use fairly standard chipsets and don't use fancy graphics switching between embedded and dedicated gpus. You shouldn't need to use TLP or do much hackery. But to avoid heartache, I definitely recommend using a laptop where the vendor supports Linux drivers etc. I've had good experiences with the driver support with recent system76 laptops.