I've tried both now - although my first DMT experience was short-lived because I should have taken one more hit. It is not fair for me to say what I think of the pure DMT experience as a whole, but if I also draw from what I've read, I'd say that the DMT experience would be more terrifying because it feels overwhelmingly quick and strong. I'm sure that if I had taken one more hit it would have been something completely "other" to me. Ayahausca on the other hand gives some room for thought and contemplation. I think that is why, although I will try pure DMT again, I have a feeling that ayahausca is something that you can develop a deeper long-term relationship to. Cool, do let us know if you take the plunge as well :) I'd recommend reading The Antipodes of Mind by Benny Shanon if you get the chance. It is the best book about ayahausca that I've read so far.I have been reading "The Spirit Molecule" and have been thinking about a DMT and/or Ayahuasca experience for sometime.
I find it interesting that you have decided to go down this path, as I may eventually do, because several of your other views on life, humanity, and evolution, etc are commensurate with my own.
I see you mention psyclobin down-thread and I'm just jumping in to say that shrooms sound like something you would like to do and I'd recommend them over a straight DMT trip for another "experience" if this is what you are looking for. However, I don't have anything to back up those statements except "folklore" - the amassed collection of stories from my friends and their usage - and, I admit, my own experience.