You can't ride most bosses as the mobs have ranged attacks that are still able to hit you, you'd be dead in 3 seconds. Page 65 is indeed hard but also gives a lot of sacrifice items for boss quests (originally, the pages are useless now because the sacrifice items are free in the shop).
If you are going to point out to me that the schoolquest boss is extremely easy to ride because of the lack of ranged mobs then think again
, that quest is still getting revamped to close range mobs and ranged mobs (if StephanM is still working on that though).
So again, bosses should give the highest exp, not the rounds, give people some motivation to actually kill bosses and not spam some rounds for huge amounts of exp. (or just delete the boss-quests as it is and make some custom well balanced quests).