Sur Incises: Modern Masterpiece?

This piece is really a masterpiece in my opinion, which achieves both structural rigor and sensuous timbral imagination. It's a marvelous creation of the late, mature Boulez, an antidote to those who view him as an avatar of avant-garde academicism (sorry for the alliteration, I couldn't help it). This is the Boulez who was formed by the thinking of Mallarme and Paul Klee: a real theorist of musical color, whose best music effortlessly fluctuates between delicate restraint and violent explosion. Sur Incises also has a kind of intimacy and sensitivity to resonance: his chosen instrumentation functions as a "deconstruction" of the piano timbre, not in order to invalidate it, but in order to more fully reveal what lies beneath its surface. So there's almost a connection to spectralism. Any other Pierre Boulez fans out there?