I've never vaped it though it's probably a good way to do it, I hear it still takes hours to kick in all the way. Rectal admin, with the freebase, is quite easy and is my preferred ROA. All you need to do is get like 3mL of warm water in a shot glass. Put your dose of freebase in, it won't dissolve of course but will sit on the top. Stir it a bit, and take some vinegar or citric acid (lemon juice would work) and drip a few drops in. Stir and some of the freebase should start to dissolve. Keep adding a bit of acid until it's all dissolved. Then you're good to go (shot glasses have rounded bottoms which makes it easier to get all of the liquid drawn up.
AMT is one of my favorite drugs. My favorite dose is about 50mg freebase, or about 80mg of the succinate salt which is what I have. I find it to take a good few hours to peak, but then it's a lot like MDMA but more clearheaded and psychedelic. It gives me a lot of confidence and the body and mental highs are wonderful. If I combine it with phenibut it's even better. It lasts a long time, and then very slowly comes down, there is never a lossy sort of feeling. Very satisfying drug. Occasionally I get a headache on the comedown but not always.