Have you actually held a Nexus 7? I was surprised at how little I cared about the plastic casing. Also, physical buttons present something of a slippery slope: realistically, I'd like more buttons than the iPad. About 4 is sufficient (plus power and volume) based on other Android handsets I've owned. But trying to find a non-awkward place to put four hardware buttons would be an exercise in frustration. Especially when you support two orientations.