My first pattern ship had goldberg retracts. Not very good in the long run for me. My second used spring air. Good quality just have to slow down the speed with line restrictors. Air pressure was a bit of a pin in the butt though. After that I switched to mechanical, usually MK or supra. Both high quality although there were two lnes ok MK. One aluminum the other plastic. Always using 1 servo so the nose gear could be a bit of a linkage problem. I would only use mechanical in a standard pattern plane after trying all of the above.

Stuart C.