[Samsung Galaxy Nexus] 7175:
I think I can help you, sorry in advance for any chain-smoking-style-rambling. I also have the Verizon/Toro Galaxy Nexus. I'm a crackflasher and have flashed pretty much every rom and kernel on Android 4.2.1 december to present. My daily driver is basically TWRP recovery. I'm pretty obsessed with flashing kernels and optimizing battery life and performance. For a straight-up solid answer for a great rom and kernel, I highly recommend: [ROM] XenonHD Stable-4.0 (03.02.13) and [KERNEL][4.2.x] Fancy Kernel (Rel. #4) (FEB-05-2013). XenonHD-Stable-4.0 is on the newly released JB 4.2.1_r1.2 JOP40G and is loaded with tons of settings-imbedded features. It's has a good user interface where you can get into more advanced features when you get a better feel for things, like PIE toggles, aokp navbar, aokp notification bar customizations, propmodder. CM is also a great starting point and one of my favorite roms, so if everything's working well, I'd stay on that and flash kernels.

I highly recommend fancy kernel rel.4 because the battery life is better than any other recent kernel I've tested (all kernels on xda and rootzwiki development back 5 pages), and this is with it flashed without any tcp congestion/IO scheduler/governor/gov.settings/frequency/gpu/voltage/etc... tweaking. I do pretty extensive tests on screen time/idle/benchmark-gpu. I've only been runny fancy kernel on XeHD for a day but everything checks out so far and battery life is amazing, so it's a good place to start. This kernel has a load of settings you can tweak in a kernel tuning app; I suggest Trickster Mod, most people use it, it's free and reliable, and it stays updated to support the major kernel features. Most roms have some minimal settings for kernel tweaking, but Trickster includes color settings, special features, and governor control. ******The other thing is that if you screw up undervolting or something and have "set on boot" enabled, you can just wipe cache/dalvik to clear those settings. PGM can also be disabled this way. Not sure about other kernel tuners.****** Besides trickster mod, I would get the pimpmyrom app for buildprop, initd, sysctl, etc tweaks

Other great, recently-updated kernels to try are: AK/Anarkia/Purity, Fancy, AIR, Starkissed, Franco, Faux, ZenSeries, leankernel, Tinykernel, Fugumod, Trinity

That list is pretty much ordered as most-->least available kernel settings. All of these have been reliable for me on aosp and aokp at some point in the past couple months, especially leankernel, ZenSeries, and Tinykernel. I recommend tinykernel or leankernel as solid kernels if you don't want to do any undervolting or fancy doesn't work out somehow. Also I'd check a few pages back when you're looking for roms/kernels since there are so many.

Some basic solid kernel settings to use:

tcp congestion algorithm=[westwood or cubic];

IO scheduler=[SIO/1024MB] cache readahead;

MPU governor=[interactive(very reliable and good performance) or ondemandplus(new and battery saving) or intellidemand(reliable and battery saving];

WIFI High Performance=ON

For good screen colors/contrast, change the color multiplier ratio so it is 1-1-1.59, i.e. 90-90-143

This page has some good minimum undervolting settings to start at for MPU(cpu),CORE(gpu), and IVA(audio,video).

For regulator voltages, these are minimum values to try(from GLadOS thread. I've tried them all stable. VUSIM should be set at 1800 min though for wifi.

;

VANA: 1000 mV

V2V1: 1000 mV

VAUX3_6030: 2500 mV

VAUX1_6030: 1000 mV

VDAC: 1000 mV

VCXIO: 1000 mV

VUSIM: 1400 mV

VMMC: 1000 mV

VUSB: 3300 mV

;

::edit::Forgot stock regulator voltages, should probably include those... also some explanations of each voltage would be good to know. :) (All from GLadOS link above, can't quote yet):

default regulator_voltages

;

VANA: 2100 mV

V2V1: 2100 mV

VAUX3_6030: 3100 mV

VAUX1_6030: 3000 mV

VDAC: 1800 mV

VCXIO: 1800 mV

VUSIM: 2200 mV

VMMC: 1800 mV

VUSB: 3300 mV

;

;

VANA: used by General Purpose Analog Digital Converter, which supplies analog circuits like battery gauge, thermal sensor, etc.

V2V1: used by TWL6040 Audio IC

VAUX3_6030: used by Display Panel

VAUX1_6030: used by Touchscreen controller?

VDAC: used by HDMI circuit?

VCXIO: used by 38.4MHz oscillator?

VUSIM: used by Display Panel

VMMC: used by SDMMC cardcage

VUSB: used by USB transceiver

;

Hope that helps with kernels. :D There's a lot more information out there. GNex development updates are frequent.

If you want to try a bunch of mods without all the searching, coordinating, try JBSourcery rom. This rom has more options and mods than anything out there. It's pretty amazing. Most other roms are gonna be CM or AOKP with cherry picked features, but this one has over 3GB mods.