IME people will go for the frag thats on rubble before the same frag on a plug unless its something they really want. thats definatly a generalization but I have parted with a frag or two and generally try to use rubble whenever possible because poeple seem to like it better as its more e4asily incorperated into the natural (yeah right) look of their tank. take corals and fish from 5 different oceans and put them in the same tank and its supposed to look natural, thats a hoot but I'm sure you underrstand what I'm saying.