I've been using my Nexus 7 for a few days and it is a pretty good tablet environment. While the Jelly Bean version if the Android OS more advanced than the Android OS on m now two year old HTC EVO phone, the system is more similar than I expected.

The seven inch size is a bit small for reading web pages. I haven't tried reading a book on the Nexus yet but suspect it should better than the Kindle Fire because the screen is of a higher resolution than the Kindle.

One side effect of having the same OS on a tablet and phone. Is a blending of form factor so you have to think about which device you are. Something iPhone/iPad users deal with too.