Hey, Nark. How are ya man? Good to have ya around again.
As for phenibut, I don't have any experience with it. I honestly never even heard of it until I was part of an online community. From what I read though is that it's not as dangerous as benzos in regard to withdrawal. It seems the research is all over the board so to speak...with varying opinions and contradicting findings.
Benzos seem to be an agonist primarily at GABA (A) in the brain. Phenibut acts primarily on GABA (B) with little to no action at GABA (A). I think this is why there isn't such a dramatic withdrawal from phenibut (i.e. seizures)
I think it's interesting to note that, although the two drugs are very different, phenibut is accepted and used in Russia, whereas methadone is banned in Russia.