I fly mine with the 46AX and love it. When I put on a Jett muffler and tuned it, it would sustain knife edge with a 10 x 6 APC. I have the CG about a quarter inch behind the recommended and have 5 points of down elevator mixed in with rudder, it has NO roll coupling at all.......great flying plane. Check out this review and build, it has some good ideas for the Tower Kaos build.
http://masportaviator.com/2007/11/16/kaos-40-mk-ii-arf/