Here is a link to a set of retracts that are mechanical but yet aluminum frame, kinda best of both worlds i thought.
http://www.3dxhobbies.com/Mechanical..._p/buz4060.htm
I got the link over in the kit building forum and guys used them in the GP Ultra Sports. I personally have not used them and they are a little pricey for mechanicals but thought i would throw out the link for ya. Oh and they are listed out of stock at the moment but expected for delivery in Feb. a little birdy told me. My thought on hobbico's were they wiggled to much in the plastic frame. They did work ok but really wiggled.