Note-perfect direction, pacing, script and performances make this one of the eeriest, creepiest and unique horror films I have ever seen, and from Roeg's very strong run of films. Perhaps the finest 'reveal' of all time, in fact.
In short, a 'must-see' film, and if you enjoy beautifully-shot psychological horror, it's definitely worth a purchase in the finest quality print available, and re-watches...hopefully once every Halloween season, in fact.