I have kind of always accepted the bad acting as a part of the 60s/70s giallo style. To me, it's just as much a part of Argento's edge as his red-orange blood and his radical (preferably Goblin) music. I just kind of accept it and, in a way, take comfort in the horrible dialogue these macabre time pieces contain.
But yeah, I agree; I think, visually, Argento is one of the most unique and creative filmmakers to come out of Italian cinema, and I happen to love most everything he's done. In fact, Profondo Rosso (Deep Red) is one of my favorite movies of all time. It just bleeds (sometimes quite literally) with creepy style and genuine fright, and has a little mix of classic detective noir.
__________________
|