I disagree. Air retracts work great at first, but in time, leaks can develop, and they must be recharged before each flight. One of the biggest problems with mechanicals is the massive amount of strain that gets put on the system. These retracts work with VERY little pressure, so there is minimal strain on the pushrods and the servo.

Once my retracts are installed and adjusted, I've never had to mess with them again - with the exception of having to occasionally straighten the struts (which you have to do with ANY retracts with wire struts)