Diph has a lifespan of 6 to 8 hours and an afterglow of lingering effects for a few hours. Datura
lasts longer but it can also be extremely dangerous.
Datura also does not produce the drunk feeling diph does, it just give you a real hazy high and for a friend of mine made him very energetic. My friend is convinced the dose he took was weak, as he experienced nothing out of the ordinary. The benadryl
however did a few things: he heard voices, he gets a lot of disturbance in his peripheral vision, he gets a really drunk, slow, weightless feeling. My friend has also seen invisible critters that were completely transparent as if they were ghosts. My friend has never experienced having a conversation with someone only to find out later they never existed in the first place and vanish.
My friend would like to revise what he wrote a little, he's never had any conversations with people he "saw" that didn't exist, but he has a few times interacted with disembodied voices.
This friend of mine is giving datura another shot soon, in a little bit of a larger dose, he will post here if he notices anything noteworthy.