I got my first Andoird phone (Nexus 5) in November. Been using everything stock (except Nova launcher) until now. I need to RMA it for some pixel issues. When I get the new one, I'm planning on rooting and flashing a custom kernel (to underclock/undervolt and help battery), and a custom ROM (for UI improvements). I was HOPING to be able to use Cyanogenmod with either Franco or ElementalX, but it seems like most of the popular kernels (Franco, Elemental, Faux, etc.) are not compatible with Cyanogenmod.

So my question is - are there any CM compatible kernels that offer the same improvement to battery life as Franco/Elemental? Or, are there any widely used and popular custom ROMs out there that offer the same level of customization in terms of lock screen, gestures, settings, etc.?

On top of improvements to battery life and UI, I'd also like to get a bit better audio quality in terms of sound and volume. Not sure how that's possible, but if it is, it's something to consider.

I was attempting to install cyanogenmod the other day actually, but it kept crashing during the detecting device stage; i may do it manually....

I've never thought about using custom kernels or anything like that though...

Kernel is kernel, rom is rom. Shouldn't be compatibility issues afaik. Not only that but I am sure if you go on xda you will find about everything for a phone with as many developers as the nexus 5.

Xda has about 76,284,869,272,596^65 posts about it. Hard for me to filter it through. What I did find on xda is that certain kernels and roms use certain protocols? CAF or AOSPwhatever they mean. CM apparantly uses CAF kernels whereas franco os AOSP

if it ain't broke, don't fix it ;)

Shows how much I have been paying attention, didn't even know CM changed from 10 to 11. Been using CAF all this time and had no idea. Odd change.

Anyways you can check original development section and probably find an AOSP but CM like rom.
Surely exist good kernels for nexus 5 and CM though too. If my dinosaur pre-NEON instruction phone has them, the nexus 5 does too.

Improving =/= fixing