I used it at a birthday party a few years ago. My main takeaways were twofold:
First, it made me understand the concept of good and bad "vibes" w.r.t. to drug use. It was clear that the experience of taking LSD recreationally in a group of people was a much a social experience as a chemical one. Keeping the "vibe" positive, by playing the right kind of music, staying chill, and saying and doing the right things, was important not to break the spell. Unfortunately, as somebody who suffers from social anxiety, this awareness made things quite stressful for me at times, as I felt I had to constantly maintain some level of self-regulation, which was not made easier by how intoxicated I was. I have the same problem when smoking weed in company.
Second, while I hoped for the kind of psychological breakthroughs and revelations that some people describe having using LSD, I didn't experience them. I never felt connected to the universe or some greater purpose. I certainly had periods of intense introspection, but they didn't reveal anything to my about my character I wasn't already aware of. I think part of that was that I was already in my mid-thirties at the time, and had done plenty of introspection over the years. I already had a good understanding of my own character — my strengths, weaknesses, hopes, fears and regrets — and I suspect anybody with a similar disposition won't have any breakthroughs using LSD.
Ultimately, I didn't regret trying LSD, but it didn't leave me with any desire to try it again. Despite its reputation, it just seemed like another drug to me. Stronger in its effect than most, but I never felt like a child of the universe, I just felt high.