I have a Sundancer 50 and Mayhem 90. I found both to be very well constructed. I built a small Sig flight box that was very nice and recently built the balancer. I was a little disappointed in the ply in the balancer as it seems a bit soft, but it works very well and is less flimsy than the Great Planes balancing machine. In addition, I screwed up one of the beams and Sig sent me a new one at no charge. I find Sig to be a good company.