I've been doing LSD since 1964 and LSD is LSD. The same as it ever was.
However in the mid to late 60's LSD tended to dosed in much more varied quantities, depending on who you got it from. Albert Hoffman had determined that 100ugs was a "standard" dose, however people producing it laid it down in varying strengths. There was a period of time when it was largely available in tablets averaging 350 to 500ugs per tab and was sold clearly as 4-way hits, meaning that it was expected that you would divide the tab into smaller doses before consuming. Many people, myself included, used it at this dosage, although it is not entirely advisable. It is, however, essentially the same molecule that is distributed today.