This thread apparently never dies!
I think the never ending arguments about who is more powerful, Gandalf or the Witchking, are beside the point.
In the book the moment when they are poised against each other at the gate is full of tension, just
because it is not clear to the reader who might be stronger. Gandalf is not without fear (as Pippin notices, in the book), but to show him thrown to the ground and looking helpless and hopeless is so out of character. He should just stand there and
not give way. The dramatic moments are obviously never dramatic enough for PJ - he has always the tendency to overdo them, which, for me at least, ruins them. (Same with the Sammath Naur scene)