I agree that ayahuasca is more for 'fine tuning' if you will - it is something to work with on a more regular basis for one thing. Integration of iboga can be tricky, and the way a 'flood' is dosed is part of the reason. It is inadvisable to flood in rapid succession (a flood dose being 15mg/kg or higher) for health concerns among other things.
Often people will boost (about 1/4 flood dose) in the weeks following a flood - this helps a great deal with integrating the experience. The session lasts a very long time and there is so much information it can take a lot out of you. Full recovery time after a deep flood can last a week. As has been mentioned, iboga is very heavy ("earth moving equipment", I like that) and frankly there is very little pleasantness about a big dose, but in my opinion and experience, it is the premiere tool for facing demons...I found iboga to have a very loving spirit - paradoxically gentle in its strength. It seemed masculine, like a loving father or grandfather. I was addicted to opiates and had many other demons to face, with this incredible medicine I was able to do so in a way I had only dreamt about. I also found that other entheogens took on much more personality and depth after iboga.
All these plants are Big medicine, but for certain things I think iboga is peerless. Working with other entheogens takes on a new dimension entirely after this. Its like it scrubs you out so clean - you're just primed for anything else.
Total and utter cosmic stuff