I have indeed seen this and I quite liked it. This movie practically invented many of the slasher movie tropes. Also it has some pretty cool camera work and a fitting OST. Nowadays it doesn't seem so impressive anymore, which is why you have to view it as a peace of cinema history.
By the way, I was thinking about your "cerebral horror movie" thread. Have you seen these:
(German Horror Movies)
Nosferatu by Friedrich Willhelm Murnau, 1922 (Max Schreck is probably the greatest horror movie actor of all time)
The Cabinet of Dr. Caligari by Robert Wiene, 1920 (the greatest set design you will ever witness)
Nosferatu, Phantom der Nacht by Werner Herzog, 1978 (OST by the one and only Popol Vuh)
Funny Games by Michael Haneke, 1997 (technically Austrian, a great twist on many popular horror tropes)
(Body Horror)
eXistenZ by David Cronenberg, 1999 (probably the best movie of the genre, tied with Eraserhead)
Taxidermia by Györgio Palfi, 2006 (more dark comedy than horror, but absolutely hilarious and morbid)
Tetsuo: The Iron Man by Shinya Tsakumoto, 1989 (there is nothing cerebral about this, it's just gore & metal)
Ichi the Killer by Takashi Miike, 2001 (
high impact violence)
(Too weird for any category)
Santa Sangre by Alejandro Jodorowski, 1989 (by any means just watch this, it has a Christ figure, tons of midgets, disgusting ritual sacrifice, an elephant burial, acid on genital action.. A must see for any horror fan)
Dellamorte Dellamore, otherwise known as Cementary Man in the US by Michele Soavi, 1994 (an Italian-French-German dark comedy masked as a zombie flick, with absolutely touching characters, some gruesome scenes and a beyond beautiful ending. This film is practically unknown, the definition of a gem in the dirt)
Freaks by Tod Browning, 1932 (from the guy who made the o.g. Dracula and many Lon Chaney films comes this absolute masterpiece. Warning: highly emotional, not really horror but still more horror than drama imo. One of my all time favorite movies)
Viridiana by Luis Bunuel, 1961 (Also hardly a horror movie, but the ending is very horrifying. Fits in with most of the religious themed horror movies just fine. This movie A deeply disturbing movie, the end will leave you completely shattered, trust me)
You seem like the kind of guy who actually goes out and listens to recommendations, so I don't feel like my time was wasted for this

Have fun and please do tell me what you think if you have/haven't/going to see these, via PM or in one of the threads.