I think that is a very reasonable option and would take care of most issues people have.
The only caveat is that I would like to see them increase the cap as overall usage goes up.
With LTE, I would expect this to be in the neighborhood of 30-50+GBs.
I`m in Japan and there are no caps on usage. 3G works everywhere, and I mean *everywhere*, and I have never heard about any problems with capacty whatsoever. Voice plans are also much cheaper here.