It depends on what and how much and how dark you're toasting. It also depends on whether you're starting with a cold (i.e. room temp) interior or one that's already heated up from the previous toasting or other use. For us, the first two slices of multi-grain bread, medium darkness (setting #4), are done in four minutes. Two frozen bagel halves take five minutes. Banana bread, for some reason, takes a little longer.
I wonder how quickly the Breville makes toast, and how subjectively powerful the broiler is. If it's as good as all that, I may decide my brick oven is truly a brick.
I haven't used the broiler much, but keeping in mind the size of the unit, it seems pretty efficient and even-heating to me.