The 537's?? I love em.. I have used them in a couple of other planes since. They are not real fast but they hold well.. I just would not go really fast with them on a plane with large surfaces and use a lot of deflection. The Tribute is a 3D plane which means you fly SLOOOW.. If yougo too fast and get on the surfaces you are risking flutter with this or any other plane of similar size and design. They worked great on my H9 Spitfie and I am putting them on the ailerons for my new Mojo 60. I am using digitals on the rudder and elevator but that would be overkill on the ailerons.