I love the interaction between Hit the Dirt! and Return Fire. It even makes me excited to get to 20th for Slingers Reflexes. Running Reload is a solid feat as well, with a decent amount of flavour build in.
If we could get a feat, at maybe around 12th level, wherein using the Hit the Dirt! reaction allows you to gain the benefits of Running Reload, while also triggering Return Fire, that would be great.
It goes along with the whole "Gunslinger Dodge" fantasy, while also allowing for an additional attack, to make up for the one which would otherwise be eaten by a regular reload action.