When it comes to difficulty, Savage, Ex and Ultimate are totally fine. Same for most leveling dungeons.

But any dungeon on 50/60/70/80/90 needs to be harder. They are so easy, you cant even wipe them. Having a WAR in your group, who needs a healer? Ironically, those dungeons are labeled as "expert" dungeons. This moment when the hard mode is easier than the normal mode.

And 24 man raids are way to easy, too. In a normal group, you spent maybe 20 mins in it. But if feels like an eternity, because each boss fight is just doing damage, do one heal and maybe make a step to the side. I would prefer an intense 5 min boss fight over a boring 10 min boss fight.