I downloaded the patch... and couldn't get past the first loading screen!

I just replaced the patch.pak file with my orginal vanilla version, leaving the other updated files as they were post-patch, and haven't had any problems so far (early days...); but it has completely fixed the stuttering sound issues in intro/duelling movies.

Might be worth a try for anyone having major problems, but I suppose you will lose any other changes they've made to patch.pak in the various patches/fixes.