My clown is always found on my wood, but always viewable. When the lights go off, he wandered all over the tank. He's on the glass every night and also eats algae wafers. He doesn't appear to be shy. In fact, I was rearranging the tank the other day. He was attached to the top of the driftwood and I picked it (the wood) up to move it. He stayed put and didn't seem too stressed about it.
I'm not sure why they're not more popular. Color is beautiful, temper is nice (although he'll chase off the goldies when they try to steal his algae wafer), size is perfect, price is right.... I love mine.