I used Wug's GNex Root Toolkit and it went smooooth as butter! I had absolutely zero issues with the kit itself, the only problem I ran into was that Clockwork Recovery refused to "stay", but that was quickly resolved (I just skipped a step, accidentally).
I am not sure, but I do believe Wug is on Version 1.3 for his toolkit? Maybe there is a newer one, but v1.3 is what I used and I highly recommend it. I would still suggest reading up on how to "manually" root your phone, so that if something goes wrong you can, at the very least, narrow down the issue and most likely even be able to figure it out and resolve it yourself.
Rooting was a step that I was a bit afraid to take myself (I don't know Linux at all; Windows I know extremely well, but not Linux); I read and read and read some more but still never felt completely confident, and despite the hundreds of declarations that this phone is "un-brickable", couldn't shake the thought that Murphy's Law would strike and that if anyone could find a way to brick the unbrickable, it would be myself haha. I got my phone at a few minutes after 9:00AM (ET) on Dec 15, i.e. release day, and didn't end up unlocking/rooting it until April 2nd (just about 3 weeks ago). I have been so impressed with the phone in it's "rooted state", especially with the ROM I am using...
While everyone will offer their own suggestions as to the ROM to use, I personally think that GummyJar Nexus is an excellent "middle ground" between "Mildly-Tweaked Stock 4.0.x" and "Infinitely Tweakable & Extremely Complex". I have been using Gummy 0.9.0 since I rooted, and I have been a bit hesitant to "upgrade" to 1.0.0 as I have not heard enough about it, good or bad, to make an informed decision.
GummyNex has a lot of awesome features, including: APEX Launcher (fully customizable), Easy-to-Use but Powerful Performance Settings (including CPU control, voltage regulation, etc), comes preloaded with a custom Kernel (undervolted slightly; can't remember the name though), and comes with ROM Manager, ROM Toolbox (I highly recommend upgrading to PRO! It is awesome!),
Combined with disabling a number of apps (that I don't use), lowering screen brightness to 25-33%, a mild under-volt, and a few other "tweaks"... I went from and average of 1:45-2:15 (hr:min) of screen time before my battery hit 5% to now averaging around 3:00 or so (max is about 3:20).
That is done by keeping my phone on WiFi and disabling 4G when at home/school/work, and disabling WiFi and turning on 4G anywhere else.
Good luck!
