As i see it the resin pads should give better stoping performance but will wear out faster, ok in the dry . The metal pads have slightly less stopping power but will last longer especialy in wet conditons . Be carefull though some manufacturers specify the type of pads you should use i.e some shimano rotors should only be used with resin pads and magura say if you use non magura pads in their brakes you void the warranty.
