Retained springs all the way.
Cones loses their tensile strength over the same relative time period. Cones are more susceptible to damage and degradation from oil and derivatives. Lets face it, cones are more of a fixed or inert suspension component.
The same natural forces acts on both, however, their individual response differs due to their dynamicity (or lack of). These two components are designed for similar, but not identical purpose..... a retained spring simply allows for a greater natural response under varying conditions...in our case off-roading...........
I will probably hear "stuff" about this......
