I have the Robard 90* 608 HD (heavy duty), they are very robust with a 3/16" strut. The US60 does lend itself very well to retracts, and far as being crowded...not at all. 5 servos (without flaps) typical 3 in the fuse side by side, elevator, rudder, throttle, 2 in the wing, aileron and retract. In case you didn't know mechinal retracts takes a special 180* servo also. Here in a picture of my wing servo arangement as per plans. Mocked up it worked very well with no binding it interference. The struts are kinda stubby also reducing the amount of wobble in will have on the runway. Notice how the retract servo is recessed into the wing.