Thanks to everyone for your replies. The one thing that I'm not crazy about with the Spring Air retracts is that when the system is not pressurized, the gear will be in the down position. When I used Rhom-Air retracts, they stayed in the position that they were left in. This new project will most likely be a Dirty Birdy 40. I’m not sure that there will be enough room in the servo compartment (in the fuse) if I were to use (2) servo’s for mechanical retracts. I do realize that I will need a 4th servo in the fuse anyway, but at least with pneumatics, the servo could be a micro servo if needed. The other option would be to use only (1) servo for mechanical retracts, but that presents its own problems. I guess I’ll have to think a little more in regards to which type I will finally use.