I have come full circle, and feel the availability of Crimson Trace laser grips is approaching essential on my primary CCW carry pistol. There are excellent waterproof military model CT laser grips available for the Beretta and Sig, and even laser grip models for the CZ (both full size and P01) and certain Gen 3 S&W pistols. In particular, the military model CT products for the Beretta 92 series and Sig 226, are the single best laser products I have used. I wish they were available for the S&W 1066/1076, but at least it generally doesn't get dark when I am carrying 10mm.
Here is why. I need glasses or contact lenses for distance vision. At night, I am significantly nearsighted without corrective lenses, but can still see a laser. Last year, I had some eye issues that effected my dominant eye. Those issues resulted in me needing to use my non dominant eye, until my dominant eye healed. A laser made the whole dominant/non-dominant eye thing significantly easier. During winter months I often recreate in the dark with a headlamp. A headlamp puts light in a bad place for iron sights, requiring me to turn off the headlamp to effectively use iron sights. With the laser, that becomes a non-issue.
I understand there can be an issue for some with inadvertent laser activation. Often, my concern is animals, where a laser ND is not an issue. With my normal very high grip, I have to consciously activate the laser, and have added a small piece of plastic under the CT activation button to make the button more sensitive. My grips also have an easy on/off switch allowing me to easily turn the laser off.