4-HO-MET: a deeper, smoother, more sedating and emotional version of 4-AcO-MET's cold, crystal clear eye candy. They're both childlike, but 4-HO-MET is deeper and warmer and more interesting, while 4-AcO-MET is more recreational and refreshing. The internet consensus is that 4-HO-MET is a gem, now supplanting 4-HO-MiPT and 4-AcO-DMT as the internet's favorite 4-sub.
4-xxx-DET: No idea, no internet consensus
4-xxx-DPT: No idea. The internet says that it's shallow and easygoing compared to N,N-DPT. Also a pain in the ass to get the dose right due to inconsistent bioavailability. Some people insufflate it because of this. Tremory/seizurey maybe with some muscle side-effects, although these don't appear to be common side effects.
4-xxx-EPT: Light, pastel confection. They lie to you, telling me everything is right with the world even when it definitely isn't. They're kind to me, but also not challenging or insightful.
4-xxx-MiPT: Impossible to classify. Is it primal or cyberpunk digital? Is it rich or thin? Is it alien or organic? I don't know. They definitely make me enjoy things: my body, food, touch, and narrative. I find them recreational and not insightful, but they can really bring attention and emotion to interpersonal relationships, refreshing appreciation for the love you feel for those that are important to you. Sometimes it all goes sideways and you just end up kinda stoned.
4-xxx-MPT: A warm, gilded relative of 4-xxx-DMT. Baroque and rich, this has depth without being as confronting. It's less harsh, but less earthy and grounded. Is it as honest? That I don't know. Sometimes it whiffs completely and is just a generic, blunting tryptamine like 4-xxx-MALT.
N,N-DPT: It's had books written about it. It's a mega-classic on par with the classical biggies. It's also pretty polarizing--people love it or hate it. I will likely never take it a second time, but I respect it. Again with the tremors. You may not want to explore this if you are nervous about possible seizures, although it appears to have a pretty good safety record all in all.
N,N-EPT: The lightest psychedelic that I've ever used that I would still call a psychedelic, and that's when vaporized. Intimidates absolutely no one. Feels lovely in the body. Erotic and gentle. Not very visual at all, and not very insightful. Still very pleasant if you aren't looking to get your world rocked.
It depends on you. It seems like people fall into one of three camps.
1) All 4 substituted tryptamines are indistinguishable from psilocybin. There's no real difference.
2) 4-substituted tryptamines have individual variation, but there's no difference between hydroxy and acetoxy substitutions at the 2-position.
3) 2) 4-substituted tryptamines have individual variation, and there's a noticeable difference between hydroxy and acetoxy substitutions at the 2-position. This can be potency, duration, or subjective effects.
This is an oversimplification, of course. I fall into category 3. So far, acetoxy subs have been smoother, lighter, more electric, more stimulating, and more shallow. Hydroxy subs have been foggier, bumpier, more muddled, deeper, less jittery, and more insightful.
This holds true for miprocin and mipracetin. I don't really like miprocin (although I want to.) Mipracetin has all of the benefits of miprocin, but yet it seems thinner and more hollowed out, lacking miprocin's richness. Mipracetin lasts longer for me.