I have reloaded thousands of .223 Rem for my AR using the RCBS standard FL die set. Never had a problem. Of Course, my AR is a cheap DPMS with a reall sloppy chamber. (you hear that alot from the guys with real nice-$$$- guns) The gun is so cheap and the chamber is so sloppy, that I can only get 0.5 moa groups at 100 yards!
I think spending extra money on fancy dies isn't worth it if you are just shooting varmints and such or unless you run into a specific problem with your specific gun. I leave those SB dies and competition dies to the profesionals that have already spent way more money on their gun than I ever will.
Just my ranting.