Been playing with this one lately. I had wanted to try it ever since... well, ever since I first read about it here, since people made it sound fun.
Luckily, I seem to get the good effects: it seems to be pro-social, pro-sexual, anti-anxiety, anti-depressant, and not really all that trippy. There's definitely a body load/muscle tension that can be pretty serious, though. Very few visuals, even with lots of cannabis. There's a sort of open-eyed visual "glow" or "fuzz" that I can't really describe... but I mostly noticed this in the immediately-after-orgasm state of intoxication, which might be a confounding factor. Despite the body load, kinesthesia is positive; I think I might try this at a rave at some point. Dancing to music on my laptop was pretty fun.
Consistent with prior reports, this seems to be okay at low doses as a mild entactogen; at higher doses it's probably a bad psychedelic. I don't think I'm going to bother to confirm the latter case myself.
I'm sort of wondering if the strange effects by smoking are caused by pyrolysis producing 5-MeO-NMT. The N-isopropyl substituent can be removed by a radical process:
R2NCH(CH3)2 --> R2NC*(CH3)2 (loss of H to give a radical, disfavoured)
R2NC*(CH3)2 <--> R2NCO2*(CH3)2 (addition of O2, reversible)
R2NCH(CH3)2 + R2NCO2*(CH3)2 --> R2NC*(CH3)2 + R2NCOOH(CH3)2
R2NCOOH(CH3)2 --> R2NH + [decomposition products] (peroxide elimination; irreversible)
Since the carbon has three substituents and is adjacent to a nitrogen atom, it should radicalize pretty easily. That would explain both the lower potency and the changed effects. If my guess is right, injected 5-MeO-MiPT should resemble the oral effects.