It depends what type of "action" style shooting you do. Sure, most dot sights make the shooting experience better but if you have to draw from a holster then you'll also need the right equipment to do that too. A dot sight can add significantly to the pistol's overall height and not too many holsters are compatible with that type of configuration. There have been many inquiries on this board by folks who want to find the right holster to do just that kind of shooting. Most of the replies I've seen recommended some type of home holster modification to make one work.
I have an 30mm Tasco "AccuDot" on my Ruger for Bullseye style shooting and it works quite well for me.