So with "irons" what I practice for fast defensive shooting from a draw at 3-10 yards is just trying to achieve quick sight alignment. Further out the more time I spend on that process. I'm looking a bit over and through my sights. They are not in focus but they are aligned. Now if someone is attacking and is within 1-3 yards you're not going to look for alignment, just completely point shoot until(if) you can further present to do so.
If you practice with dots you can pick them up extremely fast and it allows you to quickly and accurately look through your sight focusing on the target. It's quicker than just going for sight alignment imo. Now at what distance does that matter. Idk, depends on how accurate you need to be and how quickly you need to shoot. Imo it's easier to get quicker more accurate shots(1st and follow ups) with a dot.
As far as a pros cons list, dots are mostly pros imo. Also not having parallax is a big plus imo in a high stress situation. If you need to take a precise shot, longer shot on say an active shooter, charging wild animal, etc a dot has the advantage imo. Being able to focus on your target looking through the dot making precise shots, not worrying about alignment/parallax, tracking your sight/target through your shot, etc is all a W for dots.