I tried doing layer 1 on my ilvl 203 MM hunter. Had essentially no trouble clearing up the first 11 floors and first boss. But at floor 12 I hit a brick wall with arch-suppressor laguas. Problem was that his casts hit extremely hard (about 15k) and he spams it very often while my interrupt is at 24 second cooldown. Tried trapping, soaking casts with turtle but in the end I ended up wiping and losing my lives.
Hope Blizzard tunes the bosses.