Nowhere near as bad as I'd have expected, and I bet live it came off very well. A 350kw sound system will cover a multitude of sins. I kind of see what they were going for with the vocals, but they lost the ability to do that when Newsted split. Barring that, they should have swapped halves. Some lines can be shouted but others need some tone. Hetfield really needed to handle "bleeding through your fragile skin," etc. The bigger problem was with the bridge verse, though. There's no way for them to pull off the "stop breathing" part without sequencing. Trujillo will never be a proper background singer.
Still, it's cool people got to see it, and you could hear how much they appreciated what was coming up.