Yup either way, seeing the irons helps for sure. Especially at first, when making the transition from just irons.
I've found (after carrying and shooting red dot Glocks for ~8 years now) that I don't look at the sights at all in normal shooting, but it took a lot of reps of presenting the gun correctly to get to that point. I do still use the irons occasionally though, picking up that tritium front in low light is one example. Even though I don't use the irons most of the time now, I still wouldn't set up a serious pistol without them. And by "serious", I mean a pistol that is for something more than just the shooting ranges and gun games.
