Fox gliders seem to excel at slope soaring, my modded ST Fox is quite good, but I was looking for this one and finally ordered one directly to Ming Lou (Windrider boss), he replied the same day and shipped it next day. I already fly a Windrider Bee 2 from Windrider (excellent), and one of the best slope flyers of our region flew usually a Windrider Fox (I saw him fly her by 7-8 beaufort at less than 500 g). My regular buddy for slope soaring, bought his Fox second hand, well used, and flew her. I was amazed at the range of wind she could fly, and how fast and well she flew. So I have finished building a kit for this slope glider, without rudder (optional, my ST Fox turns quite well without rudder with the adequate amount of differential on ailerons). Will try to fly her at 400g, wing profile is really very thin, I built a Nimh battery from four 750 mah AAA (hope it will not fail due to my limited soldering skills). Cheers. .