You really need to break in the new disc pads properly to avoid glazing. They aren't just "throw them in and go". Yours could be glazed, or a caliper piston could be frozen.
I have two K-H disc A-bodies, both with manual brakes. One has the 1-1/32" and the other has the 15/16" MC. There is a difference in pedal effort, but there isn't a difference in stopping power. Both also have slotted cross-drilled rotors, but that is because I like to take them on winding roads up in the Sierra and Siskiyous. Not really needed for a cruiser. They don't affect normal stops, they just help dissipate heat when you are really hitting the brakes hard over a period of time, like a track day or a 9% grade.
