If I understand this answer correctly, then the Nexus 7 (7" screen at 1280x800) should show more of a given webpage (or of anything else) than the Nexus 4 (4.7" screen at 1280x768). This means that a Nexus 7 will not simply look like an enlarged Nexus 4? It will appear to have a higher resolution, because of the "dp" value mentioned in that post?
I have a handset similar to the Nexus 4 and am considering a Nexus 7. However, if the Nexus 7 will appear as a larger version of my current handset (that is, what I see on screen at the moment will still appear on a full screen on the Nexus 7), then the purchase may not be worth it.