Ditto on the 20 ga. I have a number of 12ga. but started studying the ballistics and realized for home protection a 20ga is more than enough. I bought the 500 flex. I have the tactical stock, a hunting stock and a Pistol grip stock.
The Pistol grip is very easy to use. Almost like a big pistol, easy to maneuver, easy to go to target and excellent results at the range. I placed a Flash light with a quick switch on the Grip for easy on/off.
I also Placed a bigger safety switch, and a bigger Release for faster action in the dark.
I have it loaded with #4 buckshot. Fast, agile, easy to shoot, easy to practice with a lot of rounds in one day of shooting, less noise, less recoil, less flash and won't take out the neighbors if I have to use it.
I also thought about a Mossberg Youth in 20ga. Actually for cost that would have been a excellent option.
Note* I do not live in a war zone. I seriously doubt it would be used beyond 7 yds. No need for heat shields etc. I also was concerned about blowing out my ear drums with a 12ga.