A firesteel is about a 1000x easier to use and is a lot faster as you don't need to shave/file magnesium bits. Also those little bits have a nasty way of blowing away in the breeze.

Of all the methods to start a fire, the magnesium bar is WAY down on the my list - sits right above the "rub two sticks together" method for ease of use.

Windproof Lighter
Bic Lighter
Stormproof matches
Strike anywhere matches
Firesteel
Kitchen matches
Book matches
Spark-lite
Battery/steel wool
.
.
Magnesium bar
"Rub two sticks together"

I've never tried a blast match, primitive bow drill or plow method so I can't rank those.

Your mileage may vary.