Its a bad design for the user....If you crash and bend an arm bad enough you must purchase a new main board that has the flight controller built into it. This is good for me, I can repair most pcb layouts and reflow components but the cost of crashes will likely triple repair costs and repair times.
Motor and ESC are different than P2. ESCs have braking capability similar to Inspire. They are not in the arms but on the main PCB closer to the center of the P3. If you bend an arm, your PCB should still be fine. The only risk in the new design is if an ESC dies, you have to swap the whole board.