Doesn't surprise me at all, it's one of the main selling points for Apple.

It's fine on my laptop (Arch Linux), same as in Windows, but with an i7, GTX 660M and no optimus, and a 15.6" screen there's not much power to save.

Out of the box it is not great, but it can be tweaked to get more. Mine is plugged in most of the time, so it's not a big deal for me (and is still much more than I get on most PCs).