Let me say this.
I have a Galaxy Nexus. It won't ever get 4.4, and honestly the last time it was rock solid stable (on the factory software) was 4.1. 4.2 and 4.3 had issues, and battery life took a hit each time compared to 4.1.
I've been running CM 4.4 nightlies on my Gnex almost since they were available (the first few were pretty bad but CM fixed those issues pretty quick!). I'm now enjoying smooth sailing once again, and battery life has improved a lot.
In fact, consider this: ART runtime is not officially supported by CM but they let you use it anyway (they just tell you NOT to submit bug reports if you have it enabled). Up until yesturday all releases were "nightlies", and yesturday was the first "semi-stable" build they released, called a snapshot. Plus it's 4.4 which my device will never get from Google itself. Factor all that in, and I still wind up with a devices that's MORE stable (less crashes, glitches, freezes, reboots) then running the pure stock factory software 4.3 direct from Google. If that's not testiment to CM's ROMs I don't know what would be.
Of course be sure you read up on the specifics of rooting your device. Nexus devices are super easy to root, other devices not so much!!