My new bicolor blenny is a hoot when he's up and around, but he's still new so he's still hiding a lot. He watches absolutely everything, and seems to be quite smart. After only a week, he was willing to eat from my fingers last night like the clowns -- from the safety of a cave he could get deep into but I couldn't!
My YWG is also amusing and very watchful. He acts real tough defending his little spot of sand. I want to get him/her a mate.
The clowns mostly just play and beg for food. The male trusts me more but it otherwise more shy. He's more likely to hide in his host and is trying to convince the female to move into the BIIIG frogspawn I bought for them (instead of their little frag), it part, I think, because there is room for about 10 clowns their size to comfortable hide all the way inside where you can't see them.