I think their ideas are way too elaborate to be well-suited for Zombies gamemode. For a casual player like me there's just way too much going on and no real time to sit down and sort it out. On the WaW zombies it was simple. Kill zombies, get to basement, spam box until you get a nice weapon and repeat over and over. Then Black Ops came along and it was overwhelming for me, I couldn't really get into it. Black Ops 2 was a bit more lenient since they allowed you to drop the difficulty to easy, but it's still so much packed into a gamemode that doesn't really give you a chance to actually explore it. This is pretty blatant on Tranzit, and especially true on the new Mob of the Dead(from what I've watched of Seananner's gameplay). So much stuff jammed into the level with no time to sit down and relax and appreciate/explore the world.
Not saying it's bad, exactly... but they don't give a chance for casual players of zombies(you know, the people who die around level 15-20 or so, not the people who get to round 40+ every time they play) to appreciate all the work they put into it.