And of course that will mean we have MadMax, beyond Thunderdome
Given though that we've not really in the past been able to get speef happening very regularly... (once?) I'm not sure there would be enough interest for 2 arenas.... Especially since the majority of people (myself included) seem fine with a deadly version.
With a double level one, I was just thinking that if you wanted to make it non-lethal for a particular event, you just put a temporary dirt floor down to catch players at a safe distance, rather than them falling the entire distance and hitting the arena floor.... since really, you only need to fall 3+blocks down, so you're below the spleef floor and out of the game, if the arena was high enough, it should be easy to fit a dirt floor over the top of any lava/cactus deviousness to alter the arena for safe play on the rare occasions it would be required....