What is the proper way to judge the quality of education of a university?
The best metric is comparing the quality of current and recent graduate students, in various research outlets. If students from institute X stumble more over questions at conferences compared to those from institute Y, or if they publish in lesser venues, or produce less-solid papers (more errors, more failures to think a problem through), then you can conclude either that Y attracts better students or that Y does a better job of training students than X (I don't think it would matter, for your purposes, which it is). But this is a very labor-intensive evaluation. A second runner-up method would be to look at the job-placement histories of institutions, though getting hired often reflects politics (who your adviser knows, who hates your adviser) as much as student quality.