I was one of the early Quadrophonic adopters. I actually had a 4 channel 8 track player!
We had Quadrophonic Receiver & Headphones, which I thought was quite good. Must have been my brother who bought it because I didn't purchase it, which would then place it around '78 or '79.
Then I heard my friends new Radio Shack stereo system and I concluded good stereo beats Quad. However when I started investing in audio around year 2000. My girlfriends low cost Surround system sounded better to me than my stereo. So after that I was sold on Surround Sound. With my Bryston Model T speakers & 2 corner speaker for 4 channel stereo. I get a better soundfield than I did with 5.1 Surround, but my room dimensions is also a factor.