I only know the EDT the and the perfume well enough to comment. The ladies have had more threads on Mitsouko recently. You may already have seen some of those. Here just one of them: http://community.basenotes.net/showthread.php?t=190721&highlight=Mitsouko Purplebird compares EDP and EDT, and I have always been able to rely on her balanced judgement. Although the (older) EDT has been very good, it relaxes too soon on me. Mitsouko is the one and only fragrance I bought as pure perfume for the full price. But in terms of satisfaction, depth of fragrance, and longevity it was worth jumping across that barrier.
Off topic: did you discover the parallels between Mitsouko and Kouros yet?