Just like every other 1970's horror film - don't buy the hype.
After watching a preview for this movie, it looked like something I would really enjoy. I thought about buying the old DVD (not the remastered "Criterion" version) for a few bucks, but after reading a few online reviews that boasted about the final-reveal & groundbreaking cinematics as a new benchmark for the genre, I just knew that I needed to get the 2-disc version ...then I discovered it was on Blu-Ray (as the "Criterion" version with all the extras) and decided I would fork-out the extra money for it.
I watched it, and must point out that it was made in the 1970's, where the "mystique" of rapid editing spoke something different than it does today. Frankly I found that aspect more annoying than 'creative', and coupled with the slower pace (standard for movies of that generation), I was bored and even started drifting off to sleep.
The characters were likable & somewhat engaging, but the story-line simply followed 2-people in their day-to-day lives in Venice. Maybe I missed something, but after watching the tragedy that took them to Venice, there was no significant reference to it until the very end, when it "popped-up" out of nowhere (making me wonder why I sat through the rest of the unassociated stuff - I mean c'mon, I have a day-to-day life too, but there isn't a camera crew following me)! After sitting through the painfully long middle of this film, the end reveal was nowhere near groundbreaking, it was simply a disassociated thought wearing a similar costume to something earlier in the movie.
After watching the movie & feeling it was a waste of my afternoon, I decided to try the extra features ...I didn't get far, as the director insincerely tried to sell it like it was the greatest movie ever made. I literally felt like he was reading cue-cards in the special features, because he obviously didn't believe what he was saying.