[SkyMarshal]

The most recent Linux kernels make big improvements there. My linux laptop battery life went from ~4hrs to ~8hrs when I upgraded from Ubuntu 11.10 to 12.04. The reason is a few patches added to the kernel in 2012:

http://www.h-online.com/open/news/item/New-Linux-kernel-fixe...

That article is from Feb 2012 and mentions two big power-saving problems with the kernel, the first one patched, the second (RC6 power-saving feature in Sandy Bridge) unpatched as of the article's publish date. The second has since been patched as well, for huge power gain.

[KirinDave]

By the way, I agree that recently things can get better. I stopped trying to get the Linux laptops in Jan after about 5 months of wrangling.