If you feel you can't finish some instances, it is not because your stats sucks, it is because you haven't use all of them. This is also about how to use skills wisely. Wisely used skills combinations are stronger than good stats.
Instances are not like PVP, the basic stats are important without doubt, but we can have multiple ways to enchant them temporarily.
The basic method of passing a instance is: ALIVE! Then, we can figure out a way to kill the enemy.
The instance before are all difficulties reduced because few of you can pass. But I think we after all need some good challenges.
The revamped bosses are coming back with similar difficulties. I hope you can enjoy.