Organic pads, aka semi-metallics, are pretty much standard equipment. They don't really require much of a break in period, as they are soft. The down side to this is that you have to replace them more often. They will not wear the rotor as badly as some of the ceramic pads. Ceramic pads do a good job at fighting brake fade, but as they are very hard, they wear the rotors at a faster rate.
When you do a brake job, here are some tips and things to watch for:
Make sure that whatever type of pads and shoes you use, clean the drums and rotors well. Use brakekleen, or carb cleaner, or lacquer thinner. Use something that has a quick evaporation. If you don't clean the Cosmoline (anti-rust) coating off, you will quickly gum the pads with it and you will not stop well.
Make sure the side pins on the calipers are clean, and the pin boots are not torn. Do not use wheel bearing grease to lube the slide pins. In fact, I use nothing but the pink lube from Toyota. It's good stuff, and a little goes a long way.
Make sure to inspect the dust boots on the wheel cylinders in the rear, peel them back to inspect. If you don't see any brake fluid running down the backing plate, they are ok. Check your brake lines, all of them, they get hard over time, and leak, especially at the ends. Make sure there are no cuts or abrasions anywhere.
A failed vacuum booster, will typically cause long, hard stops, If the seal fails, you will hear a loud "hissing" sound when you step on the pedal. If the master cylinder fails, you will also find it hard to stop, and you will generally find brake fluid leaking back into the booster. And, as Ali noted, check your pedal reserve distance.