I tried a fair bit of 4-FA around 2008. Generally I found doses of 175-200mgs were required for significant effect.
My first impressions were pretty good. It had been a long time since I'd taken MDMA, so to have something that provided such a stereotypical serotonergic effect was great.
Thing is, after the first couple of hours I found the euphoria wore off and I'd get quite edgy, anxious - essentially tweaked out. I also found that every time I would take a piss, it burned pretty badly and the urine had a nasty smell. It wasn't just the urine either - my armpits stank worse than from butylone/mdpv etc.
Ultimately several grams ended up being flushed away some time ago.
I should add that I am sensitive to the side effects of stimulants - my scripted dexedrine for ADD gives me some GI upset, with diarrhoa 99% of the time so my opinion on 4-FA isn't necessarily typical and definitely assume that YMMV -> readers of this post.