chris have you done the "heymccall brake overhaul"?
Replace the sliders, make sure the pads slide completely freely on the sliders (out of the box, the replacement pads are too tight a fit, I usually 'clearance' them a bit with a grinder), replace the caliper slide bolts, and grease EVERYTHING with an excess amount of high temp brake caliper grease...
That will get rid of the mushy pedal feel and uneven/crappy pad wear 99% of the time.
If you think about it:
Can you slam on the brakes at 60mph on dry pavement and cause the ABS to kick in? If so, then the brakes are obviously stronger than the friction coefficent of the tires on the road and therefore bigger/better calipers really arent going to do much in terms of stopping power/distance (because you are still limited by how well the tires grip the road). You can have the most powerful brakes in the world, but they arent going to do much good as soon as the tires start to skid/lockup.
if that makes sense....