@Shadow Before the update the DT floor 11 looked like this (see screenshot attached of floor 11)
After the update additional def is required to be able to reach floor 11 (more avg res, def+6 in armour, 150 def mount), as monsters make 160-400 damage. Of course, a party with strong characters might do the job.
(see screenshots of floor 10, as with 1400 def i was unable to survive more than 3-4 secs)