I use it, I wont have anything but painted anymore.
This is my 40g tall that I painted the trim black and background.

when it was first filled with water

after cycle
I love it. I did mine with cheap wal-mart spray paint, used 3 cans..still have some weak spots in it but you have to have a light behind the tank to see em.
(in-tank filter is simply a canister for floss, its my water clarifier)
The only back part is that it scratches are hard to fix with the tank in place, when setting it up after its dried, use a piece of plastic sheeting or a thick towel and tape it around the painted surface then place the tank, when setting the filters use all caution when placing them, slow and steady will result in zero blemishes.