Ug... I use the motorcraft original platinum tipped plugs. They work fine, and last a long time.
My complaint on the bosh plugs is that the center electrode is too small, and wears out too quickly (around 15k in my experience).
Also when the center electrode wears down it recesses itself into the ceramic insulator, which eliminates a direct spark path from the electrode to the ground points.
Just my opinion.
I like NGK and I think that the stock double platinum motorcraft are good too.
Too many cars!!!