Daylight lasers are silly. If you have trouble seeing irons, or just want to be quicker in general, milling the slide to accept an RMR is the way to go. Hope to do this myself in the foreseeable future.
By "RMR", do you mean a reflex sight? I've been watching the development of these tiny optical sights for a few years... the seem to be getting better in quality and durability, and prices are starting to come down, too.
I'm not so sure that "daylight lasers are silly", though. When my former department went to the SIG P220, we got new holsters, and the sheriff paid for rail-mounted lasers and the holsters to go with them. Not only that, but they gave our whole department low-light training with them, so by the time I left just about every guy on patrol had a light/laser on his gun.
We had several guys use their lasers during daylight hours over the subsequent couple years. Funny thing, the sun might be shining outside, but when you chase an armed felon into a building it can get dark really, really fast...
Another observation re daylight lasers... they're "banned" in most action pistol competition, even though those matches are almost always held in daylight. Seems that lasers give the users "an unfair advantage" over their competitors. I happen to know it's true. A few years ago I shot an IDPA BUG match "off the record" with my CTC-equipped Centennial. I not only shot better than several guys that normally beat me, but I shot a better score on those stages with my 442 than I had shot with my fullsize 686 previously that day.
I've worked with my laser-fitted guns in both daylight and dark, and I can say with confidence that the lasers improve my ability to shoot tighter, faster groups at a greater distance in all but the brightest sunlight.
I haven't shot a match with a reflex sight on one of my handguns, but I expect that will be highly advantageous over iron sights as well. As soon as I get one, I'll try it out and report back here.