Well my power consumption is not really bad. Actually I'm impressed by how well Barton and the team configured power management. I can easily get battery life comparable to the Windows 10 version (based on internet reviews and comments)
I just checked powertop on my 5510 and it says I only have C1, C2, and C3 though the battery life is pretty good. I wonder if the other C states will become available with Ubuntu 16.04 and a newer kernel and if so will that make the battery life that much better??
Not sure how much but it's certainly not taking full advantage of what's possible, and the alarming quote from Intel's datasheet that the article showcases ("Caution: Long term reliability cannot be assured unless all the Low-Power Idle States are enabled") is what makes me think twich about going for Skylake-based laptop. Although the quote maybe just for legal purposes. Anyway, would really appreciate if the devs can shed some light on this front.
I read some more into this and it looks like this issue doesn't affect Xeon (makes me glad I went with that!). Also, I just upgraded to 16.04 and the following C states are now available: C2, C3, C6, C7, C8, C9, and C10.