I've done it twice with low doses -- 3 and 4 mg. The onset was only slightly faster than IM, and was about the same potency. You most likely have found similar smoking it; it still takes awhile. The aMT high is a slow rolling one, I don't think anything can be done to rush it enough to get rushes from it short of injecting it straight into your brain. Combining it with amphetamine will get you closer to what I think you're looking for.