I can not speak of a brake in (bad pun I know), because I bought the bike used.
But what I will tell you is that BB7s I have will stop on a dime and give change.
I ride a Co-Motion city view with the road BB7s and it stops this VERY heavy bike very quickly.
So quickly I need to be aware of it, fot it stops almost to quickly.
Better than my Pauls, or my Camy chours. MUCH better.