haveing had mine for a while now, i havent found anything wrong with it, ive read about people adding lots of weight etx to balance it out, all i had to do was mount the batteries just behind the fire wall to get it to balance, (balanced on the main wing spar.) and its been fine, it flies great... or it used to till i killed it. but now building another one which is built slighlty different from the last one, the fuse and fire wall are are made differently, so will have to see what happens when i get it finished.