Medium distance, if you are taking about 25yds to 50yds, then Vortex Strikefire or SightMark Red Dot are fine. Bonus Vortex does have a 2X magnification (not fast but it does work) only draw back is your field of view is reduced. Gotfish hit the mark with the Burris ext. tactical $609. Vortex also has a 1X to 4X called the Viper PST 1-4X24 for about $599.
I'm not a fan of the red dot mounted on a scope due to the fact it sticks up so high and you will hit everything and it's mother, when needed it may not be zeroed (This is in the real world, not from gun case to range for targeting, street uses or military field uses is what I'm testing my builds on, but that's just me).