I think you wrapped it up pretty well, RG!
A lot of the Nexus 7 features are part of JB, which the Galaxy might or might not get eventually.
But the 7 is just more Google oriented and pure android, since it doesn't have the TouchWiz overlay like the Galaxy has.
I'm sure I left out some other features (Bluetooth, GPS). Add the price factor and no one else gets close to the 7.