I think blue backgrounds look great too. Although they don't hide equipment as well, they seem to add a perception of increased depth to the tank...as if there is more "ocean" beyond our little reef. At least until the back is covered with coralline which kind of negates any color background.
I went to a sign company and they cut a piece of deep blue sign material to the size of my tank and it was super easy to put on. It isn't very expensive either. Unlike the backgrounds you can buy at the stores it is a little darker blue and it doesn't come lose from the back so you can still run the magna float over it without causing any wrinkles.
The solid back is a good idea, suppose it would also stop the distorted look you get with the other stuff when light shines on it but as for cleaning with a magna float, well I can't get around the back of my tank very easy
I do not use a background but I have a plywood shield hanging behind the lights and almost down to the water to shield the back from light. The tank is in a wall and it is kept dark behind it.
Paul