Well, I wouldn't hold up the Senate as a shining exemplar of "one man, one vote."
I do have one gripe. Too many people vote on the basis of the person rather than the party. In legislatures, with our system, that's usually irrational, as majorities pass laws and not individuals, majorities decide who controls committees, etc. Go ahead and vote for President based on whatever standards. But with legislatures, whatever the person you're voting for has to say is irrelevant, as it's the party platform you're endorsing.