Oh boy, not for me
I`m sure there are people who can get away with doing loads but I wouldn`t say its productive and would say it never heads somewhere good with so much acid. Its abuse after all...
I think long term use of acid makes your mind focus the same way as if you were on acid, or something similar...
However, I don`t think anyone can justfiy excessive lsd use, plenty of 60`s-70`s musicians going round the bend proves that point well...
Edit: I was thinking, looking at this thread there isn`t really enough evidence to make lsd a Shedule 1/Class A drug... I mean unless your really not ready for it or taking lots/lots at a time... Its in the same category as Heroin for fuck sake, lol