Totally prestigious. Especially international rankings are done by measures of anglo-saxion standard which is not suitable for central European style universities. That is the reason why the top ten are always tend to be American or British universities ... and then some Asian universities because they have a similar system.
Prestige and quality develop hand in hand. If quality is improved it is reflected in your prestige and prestige forces you to improve quality. I think rankings despite the debate about their underlying criteria and method, are good for both prestige and improvement of educational quality.