hitting the breaks vs gearing down (to slow the car down)?

Paul H is right. But there are times when I use compression braking to slow down a vehicle. But I have a REAR wheel drive vehicle. Compression braking on a rear wheel drive vehicle slows the car down using the rear wheels and has a tendency to keep the car in balance much better than using the brakes. Since most of the stopping force when braking comes from the front wheels, the car is out of balance.

Don't believe me? Remember riding a bicycle? The front brakes worked better than the rears. But try applying the front brakes on a bike and turning. Doesn't work too well, but you can apply the rear brakes and the bike will turn.

This also works on all wheel drive or full time four wheel drive (but to a lesser extent).

I compression brake frequently in the rain, but rarely in dry weather.

Down shifting is usually used when a long braking operation would be needed, like going down a long hill. Minor speed adjustments are normally done by removing your foot from the gas and using a bit of brake if necessary.

That also ignites your brake lights so the monster truck behind you does not turn you into road pizza!

Braking obviously wears out your brakes and gearing down produces faster wear for the rear crank bearing, clutch and trans components over time...cheaper to do brake jobs than replace engine or trans parts.

Improved control of the car (i assume its a manual shift) when you down shift.