I am on board with dead zones having more enemies and loot rooms for more variety.
I like the idea of extra rooms to explore with keys and cards, something extra to do when your there.
This reminds me of the new excursions discussed. Going up against endless hordes of zombies to find high end loot. The deeper you go and the longer you stay presents a larger risk and larger reward. The addition of excursions being an option to loot on a survival map is my favorite topic discussed for U2
Excursion post (3 of 3) The Turned [mega-post] – Excursions, loot, and complications