Because of my avatar? (which is a pregnant male leafy, image taken south of Australia around kangaroo island). No, I loved watching them in the water and photographing them; it was really quite an adventure. We had to have a safety diver over the leafy to keep it from rising in the water column and getting decompression sickness. They are cold water animals (I was pretty chilled) and need live food. I saw them at the Shedd exhibit but would never even think to try them in my own tanks. Wondrous creatures though.
Camden NJ Aquarium has them on display. Pretty interesting to look at but I don't think I'd ever want to keep them.