Speaking only of my own experience shooting 3-gun Open division with a dot-sighted pistol, your mileage may vary:
The handgun dot sight excels at hitting small (or distant) targets fast. Things like TX stars, 4" plates, and distant steel transformed from painful to routine.
For full-size targets up close, even after a lot of practice with the dot, I was never any faster than irons, and often a touch slower because of height-over-bore and muscle memory shooting irons. And that's almost certainly the kind of shooting I'll need to do if (God forbid) I end up pulling the trigger for keeps on the street.
So in summary, for me, for a carry gun, the RDS isn't worth it.
Now, as the tech improves, the sights get even more bulletproof, weather/foreign object resistant, and maybe we start to see things like integral RDS, where the battery, electronics, and wind age/elevation adjustments are built into the slide, and only the sight window sticks up, and that dot starts to appear right where the front sight used to be.... that might mean a whole new ball game.