You have to put flying wires on the verticle/horizontal stab or they will snap, very soft balsa in those areas. Also if you slam it a little too hard on a landing the fuse will snap just behind the cockpit unless you reinforce it. I ran a MDS .68 and then a Satio 1.00 on mine
and didn't need any weight for C/G correction. When i did add weight it would porpose badly and was no fun to fly. Pluses for the plane though is that it floats in for a landing and if you mix spoilerines/with elevator so that you have down spoiler w/full down(40+degrees) elevator it will do a wicked waterfall and if you add the right amount of rudder it will fall to side and wind up in a knife edge spin that rotates at a very scary rate. Its a good plane for the money but needs some attention in the areas just mentioined. Its not made to fly fast except straight up.

take care
zonk