I love red dots for target shooting. Hard to beat.

Lasers are adjustable sights.
To sight in the laser, there are 2 schools of thought:

Forstationary targets at a fixed known distance, adjust the point of aim to exactly match the point of impact at the desired distance. The bullets will slightly hit high out to that distance, and low beyond it.

For combat/defensive applications, adjust the laser so that it is parallel to the bore's axis, so that the relationship between point of aim and point of impact stays consistent over a longer distance, and still keeps you within an inch or so. For pretty much the entire range of handgun effectiveness, the shot will hit a tad high for Lasermax or any other system when the laser shares the same vertical plane as the bore, and they will hit slightly high and to the left for lasergrips, where the laser is not only lower than the barrel, but to the side as well.