It seems to be fairly well established that the Nexus 4 has had issues with not supporting USB OTG since launch (e.g. this bug report). From what I've read it's both a hardware and software issue. The hardware can't supply the necessary power and the software does not conform to the protocol in some way. I'm happy to use a Nexus 4 with an external power source (Y-cable), which should solve the power issue. What I'd like to establish though is, does Android 4.3 do anything to fix the software issue?