Thanks for posting the DT, Foro - it's the one I was most curious about, being a big DT fan.
And I'm also one of the few people alive (apparently) who likes LaBrie's voice. I think is great on this track - much better than on DT's live versions of The Number Of The Beast album.
To Invader, who "complained" about LaBrie not hitting the high scream at the end ... I think LaBrie handled that perfectly. His voice gets thin and annoying when he goes that high. By staying (relatively) low, his voice kept its power and sounded much better.
Remember, a good cover is never about merely duplicating the original note-for-note. If that's all you want, listen to the original. The challenge of a good cover is changing the song to make it your own. I'd usually rather hear a band try to do a truly new version of a cover and fail miserably than hear a note-perfect but boring cover.
There are exceptions, of course. DT is often note-perfect, and I like that because some of the covers they do (e.g. "Funeral For A Friend") are challenging, and few other bands can aspire to do those covers. And we all know about "Holy Diver" getting butchered.
But sometimes the failures can be interesting for what they attempted. In the past few days, I've heard Monster Magnet's cover of "Evil" (an old Willie Dixon blues tune, more famously covered by both Clapton and Cactus) and Grand Funk's cover of "Feelin' Alright" (a Dave Mason song most famously covered by Joe Cocker). Both of those were failures, but both of those bands radically changed the song around and at least tried to be interesting. I give them credit for having the courage to risk failing.
Edit:
Now checking out the Metallica, and that's exactly what I was talking about above. They made it their own. I fucking love it!