Must say the design principles of floating calipers eludes me. The piston comes out and pushes the inner pad which contacts the rotor. But what causes the outer pad to contact the rotor? There is no spring loaded retraction anywhere, so when foot off brakes the pads remain in contact with rotor, but not under pressure? Does not seem a great design from a wear perspective.
Floating calipers with pins is simple and cheap that is why it exists. When the inner pad is pushed into rotor there is an equal force pushing from rotor to inner caliper this force pushes the outer pad into the rotor. Due to frictional losses the pouter pad has less force on it and hence tends to wear longer. Sticky pins tend to keep the pads in contact longer as they don't allow them to "retract" from the rotor.