I have an USHAB but I am worried about using just one device. I have fallen on it many times and it worked, but recently a fall did not catch for about 3 feet and it has me very worried. I also just bought a microcender. I am looking at two systems for next time I go out top rope soloing. a) using the USHBA as a primary and then using the microsender as a secondary. or b) using the microsender as a primary and then buying a minitraxion to use as the secondary. I would think using the minitraxion as a secondary since it has teeth and as secondary should not be loaded unless the primary fails. Can you advise which is better and if the choice is suitabley safe with all the precautions taken. Ward