Yes I did, in Valence (France), with a shaman from Gabon. At the ceremony, we were something like 15 people (15 people that ingested Iboga + the shaman and his helpers)... Two persons didn't see anything (or almost anything) and I was one of them. But the other people saw a lot of things, and when they explained their visions, I was kind of frustrated.
The ceremony was divided on two nights (00h - 5 AM). They played a lot of beautiful music and we puked a lot (amazing, really : you feel something going up in your stomach and then... bwarf !!). The shaman's helpers would give us fresh bottle of water, give us paper to clean our mouthes and so on, really kind.
From time to time, the shaman went to each of us and gave us a teaspoon of Iboga, like a father to his child (maybe it has an impact, psychologically speaking). Later, he gave iboga only to the people who asked for it (I couldn't, even I had no vision : too disgusting, too hard...) ; he used to say that we hadn't to hesitate asking him for more.
So I didn't see much things but the introspection working was really potent.
On the second night, they put a white powder on our faces and set a mirror in front of us, with a candle near it ; we had to look at ourselves in the mirror : at one moment, my head disappeared (in the mirror, i mean) but it lasted just a very short moment ; at another moment, I saw an eye in the middle of my head (sorry, I don't know the word in english for "front") and I interpreted this like a capacity for me to heal people (I want to become a psychologist) ; at another moment, I saw myself with a moustache, like a man of the beginning of the 20th century.
I also have to say that I had the feeling that I could understand and know what the other people in the room thought and felt (again, this feeling of empathy, which I interpreted the same way than the eye in the middle of my head).
Well, I can't explain it entirely, it would be too long (in english). I just have to say that since March, I am more confident, I almost gave up smoking (at the time : 10-15 cigarettes a day, beginning soon after waking up + 2 or 3 joints in the evening ; now : 2 or 3 joints in the evening, with regular stops).
Ok, the list of the benefits would be too long ; this month of March 2005 will really stay in my mind as a big big benefit in my life.
If you have any question, you can send me a message if you like.