I had a kit built SSE with a 50sx and it was a VERY nice combination. I've had excellent luck with all my OS 50s. Yes they are a little more expensive but my dealer only carries OS so it is beneficial in the long run if I need parts. As for the combo it weighs like 1/3 of an ounce more than a 46fx so the combo is pretty light by SE standards. Power was good and the biggest prop I would dare use was a 12" diameter. 12x4 gives you good torque and plenty of speed. I could hover my SE pretty easily with a decent pullout on 15%, now I have the same engine on a profile with a tower pipe running 20% nitro - it's a ROCKET!

BTW - I've flow SE's with Saito 72, 56, OS 46 and 50. The four strokes just don't fit the SE's for some reason, the plane really just "fits" a good 2 stroke.