most newer cars are coming with them. the 2011 5.0 has a windage tray built into the damn pan gasket for shits sake.
also the all mighty woody of ford strokers said himself many times that a windage tray is worth it, but a girdle is garbage, just not to tear a motor down/pull the motor just for a windage tray, as its a minimal gain.
I would want to keep the 7qt's of oil in the pan, and not slopping around on my crank, slowing the motor/momentum/acceleration down.
My wife's 98 Monte Carlo has one built into the pan gasket also, but that doesn't mean he needs one. If he really wants to pull his motor to put one in, so be it. Not worth it for a street car, IMHO.
Also, you'd run one just cuz Woody says so? What if Woody said valley girdle's are the cat's ass, would you run one too? I love how some people will make a reference to a certain person that if they say to do it, you should. My buddies dad put my shortblock together. Running good. I should ask him if I should run one.
Depends. There was a dude a while back that was in Cali and wanted to run a 7 qt pan for oil longevity with the hot cali heat. But if you are in San Diego, the weather doesn't get too hot there, does it? Anywho, I would only run 5 or 6 qt's in it if it were me.