Well on the topic of fun versus hardcore, I actually can't have fun unless content is challenging, however I think that doing 60 content with level 80s can still be hard especially if you have numbers issues or only a few people or one person boxing it. The content was made for 40 people so it can still take a while if you don't have numbers. Like Twin Emperors you have to do 1 million damage to the caster boss (and 1.6 million to the melee if you have melee, otherwise....) so even at 80 that could take 10 minutes with all their warping around.