I've had the Nexus4 for about a month now, gave the girlfriend the Galaxy Nexus and upgraded myself
WISportageSX experience with the Gnex is pretty much spot on for the N4 since they are both running JellyBean free from any operator software.
I am not sure what controls you get on an iPhone with the cable, but on the Nexus phones it is pretty basic. You get play/pause, skip, and back. Those controls work with pretty much any media you are playing whether it's Pandora, mp3, etc. Song names don't show up or anything.