As Ford people, we're spoiled with the Motorcraft filters. They're cheap, sold everwhere, and always do well in the independent testing. I've never seen a need to run anything but the good old FL1A.
I run Valvoline in all my cars just out of habit, though I'm sure the Motorcraft oils are good too. The Stang gets full synthetic 10W-30.
I no of a test that was done and castol GTX came out the worst. my friend recently freshened up his engine(honda) and it has 280,000 miles on it. when we tooks the pan off and valve cover every thing looked brand new nice and clean no crud built up. he uses halvoline and runs it in all his race cars and swears by it...halvoline is just advanced autozone brand. I have also seen a handful of cars from people switching from non-synthetic to synthetic and having issues, then they switch back and problems go away.
buddy of mine blew one out on his 68. have you ever seen the guts of one? the generic white filters that have "oil filter" printed across them in black ink are better.
just one of the videos on you tube. http://www.youtube.com/watch?v=kX0xrqvlsNI
They have cardboard ends holding the pleats in place, ive seen what happens to cardboard after it gets wet.
Ill stick with Wix, Napa gold (made by wix) and FL1A.