Eu de Parfum is aftershave these days.
I've worn/tried the same fragrance in aftershave, eu de toilette and eu de parfum forms. I never noticed a difference in longevity, strength or whatever. The only thing I noticed was the increase in price, the further up the supposed performance ladder you went!
This supposed 'best mens fragrance ever' cost me £210 from a reputable seller. I'm not too sure not being able to speak/read French, but I think it's in the eu de perfum form. The reviews said it smells the same as 'Cool Water' which is about £25 for the same sized 100ML bottle. The reviews were right, it's exactly the same. Yet I've worn Cool Water in supposed lesser projection/longevity form eu de toilette and found the fragrance to last longer than the almost 9 times more in price Green Irish Tweed!!