I like retracts, but the ones that come with that Great Planes P-51 are a joke. A friend had one, and he would make some of the smoothest landings possible with that plane. He didnt bounce, and it was like it was on a rail untill it came to a stop. His retracts would ALWAYS bend.

The best retracts are air. The Robart ones are the best. Our club jet guy uses the Robart retracts with the air system. The only downside is that you can run the gear up and down alot before you loose the air pressure in the tank. The upside is, they push down alot harder so you usually dont have to worry about them sticking up.