I was really skeptical, but recently did some test runs (I was the guinea pig) of 100mg, then multiple 50mg bumps through the night. I would say 100-200mg is best, I'd recommend starting off with 150mg for really powerful roll while still remaining functional, then bumping 50mg later to lengthen the effect through the night. Anything more will just end up leaving you without any lasting euphoria, but all the stimulation (which isn't pleasant, but will feel very hollow after all the euphoria you had). Best to let the Euphoria play out then get some rest.
This stuff is the closest I've ever experienced to MDMA. In fact, since it has no depression and no comedown to it really, I'd say it's on a bit higher level than MDMA for me.
WARNING: However, I tend to want to drink a lot of liquor during the tapering off/ending the night. I ended up killing a bottle of rum and I think I had the initial stages of alcohol poisoning the next morning. Intense headache, ended up getting a vicious nosebleed (must have thinned out my blood from so much liquor) and almost passed out. Don't be stupid, and limit yourself and keep hydrated.