I enjoy that era of Argento films. IMDb says CAT O' NINE TAILS was released in May 1971, so I would have seen it in Cleveland where I'd seen BIRD WITH THE CRYSTAL PLUMAGE the year before and thrilled to it. The next one, FOUR FLIES ON GRAY VELVET, was released after I'd moved to Hollywood, and I forget which theater it played, but I believe I found the listing for it in my all too brief foray through newspapers.com last year.
I never saw any of his later films in a theater but I've enjoyed discovering them on the quality Blu-ray releases from the likes of Synapse and Arrow. And I think it's safe to say that Argento's giallos are the only giallos I like at all. I tried one or two of Fulci's, for instance, that were just yucky for yuckiness's sake, and I have no appetite for those or any others. But Argento has such a superb visual sense, and he knew how to make those films immediately draw you in and hold you.