I did a while ago. Will not do it again. Worst thing I have done. The cutouts would not close all the way and leaked like crazy. Sounded horrible. Had to buy a new mid pipe.
Think about it, how could a valve that switches exhaust flow be reliable? In the extreme conditions that the valve is in it would have to be built to a very high quality standard. A valve that could actually do this and be reliable would cost upwards of a thousand dollars IMHO.