I just installed a set of E-Flite's 25-46 sized electric retracts. The installation was a breeze, it literally took 10 minutes. They worked the first time I actuated them without a hitch with a nice slow scale actuation speed (2.5 seconds). No binding, no screwing around with servos, tweaking pushrods and endpoint adjustments, just no issues at all
Some people have commented that they are expensive ($89 - ~$125) but if I look at Robart's prices and the complexity of air systems and the unreliability of mechanical sets, I don't think they are expensive at all. I noticed E-Flite has a wide selection of retracts from 15 to 25, 46 and 60 size that are all self-contained servo-less electric, trike or mains in 85, 90 and 100 degree and they come with the axles, Y or tri-harness and well written instructions. They also have some kind of sensor that prevents current drain if one does get caught on something when actuated. So if one catches on the wheel well cause you tweaked a strut it won't kill your battery and bring the plane down.
Plug and play...
From now on if I need retracts for anything from 15 size to 60, it will be the E-Flite ones.