From a dev point of view, you shoud develop on the Nexus 4 and then test it on the others. We have various devices from Samsung, HTC, Motorola, ZTE (representing our min requirements and also the popular devices) for testing on. But primary dev is done on Nexus devices. With customised versions of Android you'll often hit issues where things don't work as they
should. Recently had a baffling bug where the code worked fine on the N4, but not on the equiv Samsung devices.
Source; I'm an Android developer