A nice setup you got there. Very clean! *envy*
I do have a suggestion/critique for ya...
Personally, I'm a huge fan of arches, caves and tunnels. Also, try to avoid symmetry. Your rock formation is fairly level across the tank. Have some higher high points and some low points as well. Include some wide spots and thin spots, too. A common technique called the "horseshoe" formation is good. This is when people make a "U" shape (looking downwards) with their rocks in their tank. This may not work since this is a room divider but maybe try an "S" shape instead. All these things (arches, caves, tunnels, asymmetrical formation, and "U"/"S" shapes) give the appearance/illusion of depth and make it more intereting for the viewer as well as the inhabitants. I love looking in crevices and seeing critters inside or seeing fish swimming between the rocks.
Rearranging rocks is a big pain, though. It takes me much longer than my arms like for me to get a good setup and I have yet to be fully satisfied with the arrangement. If you decide to do this, take your time. Plan out how youd like to make it work and start from there. Your rocks will ultimately tell you how they like to sit. Just make sure its stable.
Hope this helps.