How many Android owners have flashed a custom kernel or ROM?

I'm still on the stock OTA (4.2.1) for my Nexus 4, but just flashed the franco r18 kernel. I'm very interested to see how this may do anything with battery life.

If you have flashed a custom kernel or ROM, please say:

1) Which device(s) you have?

2) Which ROM/kernel did you flash?

3) How does it compare to your former setup?