I have owned this album since it first came out (on lovely vinyl of course) and although I have long since transferred this to CD myself, I was intrigued by this new release, so I bought it. The standard tracks are all there on disc 1 with a couple of extras, and they still sound incredibly fresh - hard to believe that so much of the great music I was lucky enough to grow up with is so old now.
Disc 2 is very interesting and unlike at least one other reviewer, I shall certainly be playing it again. To a non-musician like me, it is fascinating to hear the tracks without the vocals, both to see just how much the vocals contribute to the overall sound and melody, and also to hear all the subtle background bits that you don't/can't hear when the vocals are there. But I agree about the All Night Long Cozy Powell mix track - unlike the rest, it doesn't sound like an interesting alternate remix, it just sounds a bit of a mess.
Overall, well worth buying even if you have the original album already.
And the onions? Well, back where I worked when this came out (1979/80?), we used to regularly frequent a nearby pub for lunch, and on the jukebox there (remember those?), Since You've Been Gone was far and away the most popular track, it was played ALL the time. The pub served the most delicious steak and onion rolls, and whenever I hear this track now, I am instantly transported back to that pub, sat with a great bunch of friends and munching one of those rolls. Happy Days.