Hello BarefootScientist! Congratulations on expecting your second baby!
I'm almost six months along with my third baby, who will be my second UC. I am really excited! I do UP(unassisted pregnancy) as well. I know that Laura Shanley's website was extremely inspiring to me. I would suggest reading unassisted birth stories, and comparing them with birth stories of the sort that would be your alternative. Firsthand accounts, what the mother was thinking and feeling and experiencing... Those are what spoke to me the most. I loved so much the feeling of peace and fearlessness that came to me from reading other women's UC stories. I also got a lot out of watching UC videos on Youtube... So powerful!
I think the most important thing you need to consider about UC would be whether or not you feel comfortable being ABSOLUTELY responsible for the outcome of your birth, good or bad. I am sure that the ramifications of a "bad" outcome are clear, and you have to be ready to accept that. As for the good? There is no more divine feeling, IMO, than knowing "I
did it!". But I don't think I was prepared for the very private, and almost lonely, nature of that ecstasy, elation, and joy. You would be one of a small minority of women who can claim certain birthing autonomy. Your experience will differ hugely from most women, and I found that sharing my experience was met a lot of the time by a puzzled smile and nod, but not really acceptance. So many, no matter how natural their births, just won't be able to relate. That didn't diminish the beauty and wonder at all for me, but I knew that it was MY triumph, not something that everyone else would get excited about. I hope that makes sense.
Anyway, if you need somebody to check in with and chat about it all, feel free to PM me... The UC boards seem a lot less active than back when I had my DD.