I wouldn't recommend using custom ROMs on your Nexus devices, at least not at this time. Custom rom makers have yet to sync their roms with the latest Android versions, the Cyanogenmod team has barely even started working on CM10.1 and so does MIUI, you may use a 'tweaked' version of your stock rom or any rom based on the stock images but shall you use an other roms you'll be facing some nasty bugs especially considering that the Nexus 4 is a rather new device. There is hardly even any performance difference between stock Android 4.2 and other aftermarket roms.
Very interesting. I have a Nexus 4 and a Nexus 7. What would the benfit of using that ROM on my phone or tablet be? Aesthetics? speed?