The exact questions that were asked in those surveys were the following, almost exactly.
The question about satisfaction with democracy is this. How satisfied are you with the way democracy works in your country? And the choices of answer are the following: very satisfied; fairly satisfied; fairly dissatisfied; or very dissatisfied.
The fairness question was something like this—and this was after the election. How fairly or unfairly was the election conducted? I think the answers were these: very unfairly; somewhat unfairly; somewhat fairly; or very fairly.
These two questions are correlated, but imperfectly, and we observed differences only with respect to perceptions of fairness between PR and non-PR—only with respect to perceptions of fairness, and not with respect to overall satisfaction with democracy.
There is a correlation, but it's not overly strong. The only difference that is really clear is the difference with perceptions of fairness. In terms of satisfaction, there doesn't seem to be any significant difference.