My experience with linux power management has been alright, or at least better than my expectations. I have an asus laptop that gets f*-all battery life under windows (either 8 or 10, though it seems to be worse now) but I can usually get at least 90 minutes more out of it under linux. It took some tweaking to get to that point, and I have no macbooks to compare it to, but I think the situation isn't as grim as I see a lot of people say it is.

I'm not sure if this is a fare comparison, but my MB Air can easily get 9-10 hours of battery life (if I don't run Chrome).

I get a measured 13 hours of work time on my new T460. You're citing intuition which is awfully stale.

Can confirm this (>14h) for T460 with the large battery option and under normal 'working load'

13 hours with the extra goiter-battery? Doing what?

Let me rephrase, if for no other reason than to give you the ability to retreat to some other anatomical metaphor:

This box, with a i7-6600U, routinely idles with the screen on at 5.5-6W with a current kernel (spending almost all of that in PC7 per powertop). Your ideas about Linux power management are just plain misinformed.

I have an X1 (Yoga).

Tiny almost weightless (feels lighter than current-gen Macbook Air) laptop, and it runs between 10 to 11 hours on the battery when doing normal work (programming, mail, web, spreadsheets etc..) on wifi with pleasant screen brightness ...

Linux power management is fine today on modern hardware... (Powertop reports 5.2-5.5 watts)

Is there anything you need to do / configure, as I am not getting that sort of battery out of my X1 Carbon running Mint. (I realize I usually leave bluetooth on, and the screen at mid to high brightness and have about 20-30 tabs open in firefox but I would still be lucky to get 5 hours out of it.)

On my machine mentioned upthread, I have a third party SSD installed which apparently fools the firmware into disabling SATA link power management. Powertop will tell you about most goofs like that.

Beyond that, run a current kernel (my measurements are on Fedora's 4.8.12 kernel). Also recognize that recent Intel SoCs have gotten a lot better at idle power draw. The "X1 Carbon" brand started with (I think) Ivy Bridge boards which obviously aren't going to perform like this.

Current/modern kernel (I run Arch), disable unneeded radios (bluetooth and lte for me), slightly lower (but still nice) brigtness on the screen and agressive tuning by powertop..

Agreed. Lenovo claims "up to" 9 hours for the 3rd gen X1 carbon, I get at most 5 under linux.

That said, I still prefer my X1 to macbooks. I find the MBP 15 heavy, the air has an atrocious screen. And both make my wrists hurt when typing - the edge of the laptop is too sharp. The X1 has a great screen (QHD), is very light and has an excellent keyboard. I think the trackpad, software and battery life are better with macbooks.

It certainly does, but my XPS 13 lasts ~7 hours running Fedora 25 and my work-issued W540 gets around the same (this is a stupid beast of the machine that only gets that much running Windows, a 40W quad-core i7 in a laptop isn't power sipping when I'm building something in Visual Studio or IntelliJ). It's getting a lot better as long as you're not running a Skylake chip, Haswell/Broadwell and below have pretty decent support these days.