Just a thought on wear-

The act of slowing a car is simple- you convert inertia into heat energy. The brakes do this through friction and dissipate the energy through the rotors/pads.

Downshifting causes the engines compression to slow the vehicle. The act of downshifting does put a load on the transmission (which it is designed to do) which is transferred through various wet clutches to hold various portions of the planetaries. This does cause wear on the clutches- as this is how a transmission is designed to operate.

SO- would you rather use the cheap brake pads to slow the car- or the expensive transmission/engine to slow the car?

Both are designed to do this- but one's sole function on this planet is to slow your vehicle- the others is a little more complicated and expensive. Now if you are autocrossing- you are not worried about the minor wear on the trans/engine- you are worried about performance. But I assume none of you were autocrosing to and from work. So either will work, its up to you to decide how to drive your vehicle.