I always found a good solid 8 to 10 hours outside the borders of consensus reality was quite enough. You have to take some time afterwards to integrate the solid insights, and gently set the alleged insights that were just a flash in the brainpan aside.
My comment with that when I posted it on Facebook was, this is how I feel after watching the news these days. There are fun trips, there are intense ones, and then there are the bad ones. The news these days is the latter.