I just took a shower and the drain is very slow. I heard gurgling in the toilet. I flushed it. The water level rose to the top. Eek! Thinking there was a connection, I closed the shower drain. The toilet gurgling stopped. I waited until the toilet water was completely gone, then opened the shower drain. Glug, glug, went the toilet. Up, up, up went the water level. (Fun children's horror story, eh?) WTH? Why are they connected? I imagine that instead of each drain going down through the ceiling and walls separately, they connect in the center of the bathroom or something. NOT a good design. Any thoughts?