For Piper, I find the mono version more psychedelic-sounding. The extra reverb on the vocals makes it sound that much more ethereal - not to mention that I'm not too crazy about the certain instruments being only on one channel. Beacause it's such a wild recording, I find that the mono seems more focused. I love the stereo as well. Luckily, I never had the chance to get used to one over the other - like I did with the Beatles - and discovered the stereo and the mono at around the same time - believe it or not, when the reissue came out. I have the 3 cd set as well, unfortunately, it sounds compressed, so hoping that the vinyl will be without compression, like the rest of the reissues.