i feel absolutely no difference between NEP or Hexen. the latter maybe a little more potent. at least this is the case between a-pvp and a-php.
Then you got "strange" batches, or maybe it was me, who got the strange ones...
I tried 2 different batches of NEP and 1 of hexen,
the hexen was flour consistency, very chemical drip, strong punch pain in the nose, and fucked up bloody snots for days. The first rush was super strong, then it was useless edgy stimulation without euphoria and horrible, horrible comedown, even with few redoses.
both NEPs were more or less great, the powder tan thing was worse, but with less side effects, more sexual but with more vasoconstriction, less rush
the crystal was harder, harder rush, but harder sides apart from the vasoconstriction, both had a bit of a comedown if you abuse, but not as much as hexen
For me NEP is much more clean, more uplifting and longer lasting, content feeling and a little euphoria for an hour or two. The hexen felt toxic since the second time I tried it, the comedown was hellish, full of depressive, lethargic, I-would-like-to-be-dead feelings. not my thing
I've heard that crystal batches are much much better, but never bought one.