Another tactical consideration is that there is a growing body of anecdotal evidence from law enforcement incidents that use of the laser during the challenge phase of an armed encounter (if there's time for that) increases the chances that the felon will submit rather than fight. I read one case where the BG refused to drop his gun even when confronted by an AR15 armed officer, but dropped it in a hurry when another officer put his pistol's laser dot on the subject's chest. Go figure. I suspect the reason behind this is that the influence of movies and TV on our bad guy population is much stronger than reason itself.Tactically, the first thing to remember is that a laser can be seen in both directions.
If laser grips can increase the chances of a successful outcome from the good guy's perspective, I think they're a good (though very optional) investment. I weighed the pros and cons for a long time (several years) before I plunked down the cash to put them on my primary carry gun, and don't miss them at all when I carry other models not so equipped.