Hard to say. I instinctivly distrust anything with batteries and you can still miss if your trigger control is off.
On the other paw, if you have to shoot from a strange position, maybe the laser can help.
You still have to zero the laser.
I do not put any trust in the "put the dot on their chest and they'll back off" theory. Most folks do not look at thier chest.
For the couple of hundred dollars you'll spend for the laser, you should be able to get a couple of thousand reloads. Practice makes perfect or so they say.
FWIW, last laser I used was the size of a 4 D cell Maglite, so I'm dated.
Giz