I think one of the drawbacks of using an Android HU is the slow startup, yung iba inaadvertise nila na may quickboot, yung Win CE ng AVT I think mga 5 seconds mag boot after starting.
Pioneer if your going for purely sound, android if your going for all around functionality. Really depends what your into. The android unit would have everything a pioneer unit has.
I would always go for pioneer anyday of the week just for quality of sound.