like the black back for similar reasons as above, seems to focus on the colors of the corals, fish, etc. seemed to give more depth for me than the blue backs, but seems a matter of personal prefernce more than anything.
beautiful tank pics clkwrk!! wondering how do you keep all the sides, including the back, clean? scrape constantly? i never understand how people clean the back up so good, i always have problems cleaning coralline around the back area..