I found another application for a laser attached to a handgun: its use as a training aid. That "bouncing dot" is a heck of a good indicator of what the shooter is doing with the trigger, and his or her maintenance of a good, uniform shot to shot, grip.
Most all of us, with some experience, have noted the effects of pushing the trigger finger too far through the trigger guard and the disastrous effect this has on grouping. The laser will show you just how much of a difference it makes while dry firing or in live practice. It helps you 'tune' your grip and trigger finger placement. It showed me some things I've been doing with various hand guns for over 50 years. And for a new shooter, it reduces hours of explanation by the coach to a self evident display.
A good laser is no substitute for the fundamentals: Uniform grip shot to shot, Sight alignment, Sight picture, unwavering focus on the front sight and follow through. Used as a training aid, it makes teaching (and learning) those fundamentals easier.
YMMV, Rod