Woops sorry,
Difference is rather large. Nu Nu is toasted wild tobacco and toasted theoborma bicolor inner bark. The Matses settle near the Bicolor tree and wild tobacco as their sanctuary to be established in harmony with nature both are extra sacred to the tribe. The effects are more blunt in force to me and less joyful, honestly I don't really like Nu Nu. I find the experience to be painful and not very rewarding. In order to get visionary effects the Matses to cycles of blows from a straight bamboo tube over and over and over until TKO. So you can see it takes a lot of pain to get the gain.
Rape' pronounced Hop-A just means snuff. It comes from the tribes of the Acre region and the Santo Daime that have adopted it as a sacrament by and large. Basically the relationship of the Santo Daime to these tribes of the (main 3 although there are others) Huni Kuin, Yawanawa and Katukina has spread the use of Hop-A to the wider world. It will become more and more known as it is extremely rewarding even at small 'doses'. Blow pipes are V shaped in general although the ceremonial pipes are curved in nature with the blow side large and the nose side small. It takes a fine and clean healer to blow Hop-A as it carries there spirit. Never receive this medicine from a novice, must be a devoted healer.
Hop-A in general is wild and/or cultivated tobacco either rustica or tobacum with half being ash from a sacred and high alkalizing tree. One can attain amazing visions from this medicine and it synergizes extremely well with Ayahuasca.
That is the summation I have. Hopefully Caiano and others can chime in that have experience with both. I know some that like NuNu but I would say most of those have very little experience with Hop-A (Rape'). If they have had Hop-A enough or even a little I doubt they would consult NuNu very much anymore.