Whats better??

On a DWC system, whats better? A plastic lid that closes over or a floating platform?????

I've never used the floating platform rig, but I would guess it would be hard to keep light out of the reservoir thus you would have an algae problem.
Like I said, just a guess. I'm sure someone who's actually used this method would prove me wrong.
Good luck!

mmmm was thinking that myself!!

Another plus for the tight fitting lid is: less water lost to evaporation.

I use a dremmel tool to cut the holes neat and tight - works perfect for me,