I can't comment about a-pvp because I was in a situation where information and research were unavailable and by the time they were laws had been put in place.
Stigma it would last maybe two hours, I don't know of this menthol taste you mention as mine was definitely not at all menthol but that's just my experience. I didn't experience any withdrawal, went through a gram of each over a period of a couple days. Other than being tired on the day after they were finished I had no issues with withdrawal. Never really experienced any with MDPV use either and I went through a period of heavy heavy usage on a daily basis for about a year. I'd do it alone or mix it with MxE in the same spoon so I was definitely getting crazy. When the rug was pulled out from under me I didn't go through anything I'd consider to be 'withdrawal' other than being grumpy, having some cravings and being tired. I was lucky that the psychosis thing never got me so I can't comment on any of that either. All in all I'd say the two substances definitely have differing characteristics that would remind you of PV but of course they far from replicate all the effects. Either way I enjoyed them.
lolwhatz, I know what you're getting at but the experience I'm referring to when I mention the dosage was from insufflation not IV. I haven't experienced anything when injecting but I go much lower mg. wise obviously.
As far as euphoria JG, I can't really say that there was much with either of the compounds though they were pleasurable in their own way. Obviously when injecting most rushes if enjoyed, could be considered euphoric so I can't elaborate on it much more than that. It's mostly about stimulation with these guys and I'd say the same about MDPV. A hell of a rush but the end result wasn't euphoric by my defination.
Hope this helps.