Guess it depends on how much you like the original. I thought the Vaseline's cover done for that session was better than the original and added to song but I'm only a mild Vaselines fan. It added an emotional sincerity where I think the original came off as more intellectual. I also grew up around a lot of that folksy Jesus stuff and it hit home a bit more when he did it. Some covers also add a different tone or slight changes to invoke different moods or emotional meanings and I think these fare better as people tend to find ways to like these without them competing with there feelings on the originals. It's hard. I mean even when these covers kind of succeed they only seem in my kind to get a pass. I mean radiohead are obviously talented but even the headmaster ritual cover only gets an above average grade from me. They didn't embarrass themselves and make the song sound awkward but it still feels lifeless mainly because like you said it's the feeling the performances bring in these cases thats hard to match and for me that includes the music as well. I've seen morrissey perform songs like still ill with his recent band in 2013 and obviously with him doing the song and the music being easier to replicate than a vocal it still didn't sound like it would, has, with the smiths playing it from what I can tell from old videos or even from more recent marry versions of smiths songs. Someone trying to mimic that magic is almost certain to fail. Bring it back to nirvana unplugged I think the song Kurt probably had a harder time cover was where did you sleep last night. Giving it that screeching harrowing quality is why it succeeded so well, making it his own. If he had done it straight like the original I don't know how it would have come out. His cover of that Beatles song is another version of that direction. Even on a boom box recording it sounds great and compelling since he sang it with such a morose vocal. And I love her I think was the song. If he had done it straight like the original I think it would have failed and come off sounding sarcastic and not serious