this one comes down to basic physics - the entire process is a mere conversion of kinetic energy into thermal energy
there are 3 things at play here - pad material, rotor material, and the ability of each one to disapate the heat caused by the friction of the stopping process
soft pads disapate heat well for short durations, but do so partially by shearing off material
hard pads last longer, and can withstand the heat longer, thereby stopping better, by better transferring heat to the rotor - this is a desireable feature - they also generate less dust as a rusult, also a desireable feature
where this falls down is on the rotor's ability to then release that heat - failure to accommodate the increased heat transfer of the hard pads results in parts of the rotor wearing away under the stress - this is an undesireable feature
so, it's all about friction and heat
there are 2 kinds of friction here - abrasive friction and adherant friction
abrasive friction involves the breaking of molecular bonds between the pad material and the iron in the rotor - pads that function on this basis (organic) tend to have a high wear rate and low resistance to high-temp fade
adherant friction is developed when a transfer film of the same compound as the pad material is deposited as a very thin film on the surface of the rotor - here, the friction is caused by a breaking of molecular bonds between the two like friction materials amongst themselves (one on the pad and one on the rotor)
most performance pad manufacturers now make pads that combine these two technologies - they tend to have higher coefficients of friction over a wider range of temps
a word on noise and squeal - this is caused by high frequency vibrations of the pads - the density of the material and rigidity of it plays heavily here - this is why high metallic content pads tend to make noise - the stiffer the pad, the more likely to vibrate and squeal
to choose a pad for your use, you should focus on the driving you will do - if you are doing performance driving, with higher temps, find a pad with a temp range that is suitable - if you are driving on the street, a softer pad will be a better choice for reasons of noise, and smooth and even braking
did that make it better or worse?