I don't see the need to upgrade yet. My NT is still fully functional and runs CM10 from its 8 GB μSD card. Also, some apps can be of use to increase its capabilities. One such app is GrooveIP Lite which, when set up with Google Voice, converts the tablet into a VOIP telephone capable of making free local and long distance calls in the U.S. I actually got the idea from a YouTube video "7 Things You Must Do With Your Nexus 7" at http://www.youtube.com/watch?v=_GCiEqB5How
GrooveIP Lite worked well in my limited trial. Check it out.