For an instance content that relies on not only ones connection to stay stable but also for the servers to stay stable, one hiccup and you lose all your progress to proceed past floor 100. It's not the mobs or even the bosses that are difficult in this content but the hope that you don't d/c and lose the time spent progressing and planning ahead for future floors.

I feel SE should implement an NPC that removes -1 KO from one save when it's a server error that caused you to lose said dungeon, aka unstable servers. At least then the only variable that could hurt people while going up the dungeons is there own connection, which while it still sucks I"m ok with. However when it comes to the servers being the reason for the loss and not ones connection, they need to implement something to allow people to rollback a KO that was the servers fault.