Dragon Commando is right.
Best way to brake in a roadcar is to slam it till abs fires, then gradually reduce pressure until abs stops firing. This should get you the correct amount of pressure for threshold braking -the most effecient way to brake.
HOWEVER, as you slow down you can(and should) apply more brake pressure, as the tires can deal with it. So in practice just slam the brakes and hold on. Keep the pressure constant, abs will work for you until you stop.
OR - and this is the real kicker - learn how much pressure you have to apply (at different speeds, and at different grip levels), to brake as hard as you can without engaging the ABS. (ABS trades a little bit of braking distance of the ability to steer, and does this while keeping the braking distance way under the usual all-wheels-locked emergency braking.).
Some ABS' are more eager than others, though - my Skoda Octavia's abs is waaay too eager, while my old Xsara Picasso's ABS were a tad not eager enough. Result: With the xsara I could easily threshold brake, enabling me to brake so hard it felt your eyeballs were gonna fall off, and in my Octavia the abs engages BEFORE I could apply full brakes without locking up (or as I feel I could, from the "butt feeling" in the car - could be the tires it comes with have less grip than Im used to).
TL: DR: Dragon Command is right, your friend is DEAD WRONG (Perhaps I should put "Soon-to-be-dead" wrong), Full brake force with ABS, and learn to brake as hard as you can without locking up.