Preface: I've done all sorts of the "staple" drugs, as well as tried vaped Hex-En and 3-FPM.
I got 5g of this 4-MPD (4-methyl-pentadrone) from a vendor I've dealt with in the past.
I vaped this chem out of an oil burner and off of tin-foil. Had more success with the tinfoil. I started out with a tiny amount (.005g) 5mg. It is active at this level for those of you trying to vape this, it's very fickle, and burns easily, so be careful on how much heat you apply.
Immediate bell-ringing in the ears (not as strong as crack or IV coke, but still there, hairs tingling on the back of my neck, noticeable increase in HR, and BP, at this level it is somewhat functional)
Definite more-ishness to this substance when vaped. Each session after this (over the course of a week) I vaped between 5mg and 50mg. Re-dosing once or twice throughout the night.
Besides the initial rush and mild euphoria this chemical provided a hellish experience when trying to come down. Used benzos, opiates, diphenhydramine.
After the last dose of this don't expect to sleep for 6-8 hours.
Threw the rest away as I could definitely see this causing serious vasoconstriction and bruxism.
At least with Hex-En it was over after 30 minutes or so, this on the other hand hung around for AWHILE afterwards.
Don't waste your money on this substance if your preferred method of ROA is vaping. Didn't try IV because I didn't want to die.
Hopefully this helps someone looking into this chem.