oh, and don't forget plural and proportional voting
At least as implemented in Australia, the Hare-Clark system doesn't involve giving some people more votes than others*. In our Senate elections, six candidates must be elected, and voters list all the candidates (or all the party lists) in order of preference. Candidates who get more than the necessary number of votes (typically those at the top of the party list) have their excess votes flow on with an appropriate weight. It's complicated, but elegant.
* Except that, as in the US, each state gets the same number of Senators, so voters in small states count for more.
My response on epistocracy https://johnquiggin.com/2017/06/17/against-epistocracy/
You’ve omitted consideration of the two most libertarian and important aspects of governmental design — to minimize the likelihood that government will behave tyrannically and to minimize the overall level of coercion perpetrated in the name of govt authority.
The divided and republican nature of our constitutional system is a feature not a bug. Regional representation increases the diversity of viewpoints and the influence such viewpoints have on the exercise of govt coercion. In a word, we don’t want govt to work more smoothly. Govt is coercion and force. Obstacles are there by design.
Features like the legislature and executive representing different factions impairs the easy and efficient oppression of the governed. The best system is the one least likely to coerce people to act or forbear against their will. Proportional voting virtually guarantees majoritarian tyranny.