I have the Venus II with a YS110 and hatori 721 muffler. Excellent combination, fast acceleration and uplines with a APC 14x10. Unlimited vertical with 20/20 fuel. I have 3 servos in the rear and the muffler under the wing, and it doesn´t need any weight.
I really love this plane, great for learn and practise pattern flight, also I am using it in my club´s intermediate competition with great results.