I have done a few LSD trips. The first one was really weird, the rest were with smaller doses and less intense. They've given me a couple of mildly interesting ideas, but for the most part I don't feel like I've really gotten anything useful out of them. (I keep thinking that given the reputation that the thing has, there has to be some way of getting more out of the experiences, but for a large part it feels like my mind gets temporarily dulled by the thing so that I can't really think or do anything interesting, and then I just get bored and start waiting for the trip to be over.)

I won't be able to do it justice in words, but I like to try.

If you value your current makeup as a "rationalist" - LSD will not necessarily help with that. Whatever your current worldview, it is not "the truth", it is constructed, and it will not be the same after you come down.

You can't expect a trip to do anything in particular, except maybe blow your mind. A trip is like finding out you were adopted. It's discovering a secret hidden in plain sight. It's waking up to realize you've never been awake before - you were only dreaming you were awake. It's finding out that everything familiar, everything you took for granted, was something else all along, and you had no idea.

No matter how much you've invested in the identity of "rationalist", no matter how much science you've read... Even if you know how many stars there are in the visible universe, and how many atoms. Even if you've cultivated a sense for numbers like that, real reality is so much bigger than whatever your perception of it is. I don't know how acid works, but it seems to open you in a way that lets more of everything in. More light. More information. Reality is not what you think it is. Reality is reality. Acid may not be able to show you reality, but it can viscerally drive home that difference. It can show you that you've been living in your mind all your life, and mistaking it for reality.

It will also change your sense of self. You may find that your self-concept is like a mirage. You may experience ego-loss, which is like becoming nobody and nothing in particular, only immediate sensory awareness and thought, unconnected to what you think of as you, the person.

I don't know about health dangers. I never experienced any. Tripping does permanently change the way you view the world. It's a special case of seeing something you can't un-see. Whether it's a "benefit" ... depends a lot on what you want.