Gondry surely likes stunt film-making, but it seems to me that all his stunts have an important narrative purpose. "The Science Of Sleep" seems at first pretty messy and slapdash, but if you watch closely, Gondry is rigorous in doing what he does, and provides cues for the audience to keep things straight. It's a movie about a character who has trouble telling his dreams from real life, and you as a viewer is supposed to feel that confusion, but at the same time not _be_ confused. The best cue -- listen for it -- is that when he's dreaming the sound is all 'looped' -- i.e. filmed silent and then dialog and sound effects assembled in post production. The 'real life' sequences are all (or mostly) recorded while filming.
A movie shouldn't show off it's technical tricks -- they're a distraction. But sometimes the tricks are the thing; "The Science Of Sleep" revels in it's own artifice but still stays anchored in the emotional reality of its characters. I'm sure Joe Professional Movie Critic watches it and says "quit fucking around and tell the story!" but the point of the movie _is_ the unruly imagination.
And Charlotte Gainsbourg is awesome. She's the kind of beautiful that makes conventionally beautiful actresses look vapid and blank.