I have the XS Big Dot sights on my Shield, and think they are great for an EDC. These guys are right about long distances; however, I figure I would have a hard time claiming self-defense outside of 20 yards....
I finally got my first M4 this weekend at the 1500!!! Bought a Core 15 M4 from Zx Guns out of Goshen. They were really great, and the price was fantastic! I saved enough money with them, that I was able to dress it up with all of the Magpul FDE equipment I was after too. I'll try to post pics...