I've always been a fan of state over federal, but I don't think a lot of our states are "rich" enough to balance out the others. I'd imagine an optimal balance would be several of the lower population states be merged together based on culture until we have ~10 states with the wealth of Germany or some such, but then dumping a lot of the federal powers to before Wickard v. Filburn. The thing is that the impotence seems to kick in on the "super-large" continent sized countries, but that doesn't mean there isn't a minimum size too, of which a Vermont or Kentucky doesn't really meet compared to a Texas or California.

It should also be noted these changes would only practically be achieved with a time machine, because the social/economic/military cost of changing anything involving the foundation of the US nowadays would be apocalyptic