Brake pads work by putting down a very, very thin coating of brake pad material called a "deposition layer" on to the metal surface of brake rotors. (That's what you're doing when you're "bedding" them in.) From then on, when the brakes are hot enough the brake pad will generate friction not by grinding themselves down against the rotors, but by constantly creating and breaking molecular-level bonds with the deposition layer as it squeezes past. That produces much better braking power and much better pad life, but it only happens when they're hot. Deposition layers aren't compatible across different pad compounds (different metal mixtures, sintered metal vs carbon.. etc) so if you switch pads, you need to remove that deposition layer. There are lots of ways to do it but blasting with tiny glass beads is the most effective. (NOT simply "sandblasting" btw! Despite the name, they don't actually usually use sand - effectively tiny glass beads - they often use Aluminum Oxide, which is much harder than the steel of your rotors and grains will embed themselves in the surface, which will screw up the bedding process.)
Having done both bead blasting and rotor honing it myself I recommend the rotor hone. $40 and you can use it multiple times, BB typically cost that for 1 set of front rotors. I used a medium grit rotor hone and it took no longer than 20 mins.
