I have been to Bonnaroo and Camp Bisco.
Bonnaroo security is a bit more strict with drugs, but you can still find good stuff and you wont get hassled for lighting up a j or something. I found at Bonnaroo most of the psychedelics are pretty bunk, a long with a good portion of the MDMA. It is super fucking hot and dusty which sucks, because at times it can prevent you from seeing a show. All in all it is still a great festival with an amazing people and awesome music.
Camp Bisco is pretty close to a free for all, although this year i think they will be a little more strict. There are no cops, just hells angles that run security. The bikers don't care what you do as long as you are not selling drugs, but even then not many people are caught. The drugs are pretty good, almost all the LSD is legit but a lot of the MDMA is bunk or just bath salts. The location is great, upstate NY in july is perfect fest weather although it always rains at least once. The crows is good, not as good as Bonnaroo though. There a few different factions of people that gather at Camp Bisco every year and they sometimes clash, so the unity isn't all there. However i have met great people at camp. Lastly, if your into electronica/psychedelia it might be the best music fest in america.