Since having tried lights and every other brand, the only exception to the Pearse was the D'Angelicos, which I can't find now, I use John Pearse mediums on my Martin 0021 that brings out the balance from highs to lows. I play acoustic jazz on it from time to time and it really cuts through horns and other instruments.

John Pearse mediums seem to be the right weight and torque for the 0021 and they sound well with pick and finger style. I do have to change them every other month or so which brightens the sound considerably.

Any talk of strings has to consider the player and their technique. I play finger style softly and pick style loud. John Pearse mediums work for me.