In my experience, I have had more hit and miss experiences with Caapi. When I do manage to get it to work, it is preferable to Rue from a physical and phenomenal point of view. However I have found that Rue is usually a more succesful MAOI than Caapi, even though it usually causes some stomach discomfort and the occasional howffing session. Commercial Caapi extracts seem to often not be as potent as they claim.
I usually use a pharmahuasca analog starting with 300mgs of Moclobeminde (Mannerix), sometimes 450, followed by synthed DMT at the one hour mark. I have found that this allows a pretty good experience. There are tricks to enhance your breakthrough. For example, an empty stomach, and a DMT solution with minimal liquid volume, seems to increase absorbtion rate. If the DMT levels in your system rise too slowly, your Rocketship will leave without you! Yes it tastes foul - try to get the shot to avoid your tongue. Plugging a solution can be effective, but you want to aim for a neutral pH or you have a back passage like a gunshot wound.
I acknowledge that this is not a genuine Ayahuasca post. To be honest, I have experienced the brew in an authentic Amazonian setting near Iquitos with a good (as far as I could tell) Shaman who was not just a commercial outfit for tourists. It was a beautiful experience which was meaningful in a personal way, and also from a cultural point of view. However, the stories our Shaman told and his worldview were not always directly translatable into my own life and situation here at home. I am unlikely to have to engage in Shamanic conflict, as a Postal delivery worker.
This is why the Pharmahuasca idea is valid to my mind. It is, obviously a different experience, but I have found that it allows simillar access to levels of the mind that Ayahuasca does. There are millions of variables that come into play in terms of setting. For example, if your mindset is filled with thoughts about authenticity and you are imbibing Ayahuasca with traditional ingredients and ritual, then these factors will shape the way that you interpret the material. Or, if you have just followed a synthetic MAOI with some nice synthed spice, and you have got the latest Flying Lotus LP on the headphones, the you have a wholly different slant.
Moclobemide is relatively easily available, and a rather forgiving, transparent substance, with little dietary complication. I once ate a cheese and marmite sandwich in the aftermath (T+8hrs) with no evidence of serotonin symptoms that I could detect.
There are plenty of reports on erowid which describe interesting experiences with just Caapi or Rue. I recall one described very dimly coloured visuals. I like that description of Caapi as the cave and the DMT admixture as the torch/light.
What a ramble. Your mileage may vary - Peace - Pipp