I saw this on its original theatrical release and like it a lot, although I don't think I've watched it again in its entirety since, despite having the DVD release. Definitely a film you have to be in the mood to watch, and one that you have to pay close attention to. I've always loved the Morricone score, one of his very best.
Perversely I've always wanted to see the US theatrical version just to see what it was like -
here's Roger Ebert's review of both.