The benches are sloped slightly, but not much. Enough that water doesn't pool, but not enough for individual droplets to "roll" off instead of just sitting there.
Also, no air vents in there. I think you'll cook from steam way before the oxygen is used up. I've been keeping the door open for a bit after use to dry the place out. It could easily turn into a mold pit sitting dark and wet with no air circulation. Maybe i'll put a vent in the new door with some way to shut it off when the steam is turned on.
Also, here's the glass mosaic: