Does anybody find these recordings valuable aids to study? The experience of playing with a real orchestra, where there is collaboration (ideally!) between the soloist and other players is totally different from trying to keep up with an orchestral contribution which was recorded long ago and far away. It's a bit like following an orchestral recording and pretending to conduct, when the real job of a conductor is to direct the performers in his orchestra.
Well, you try to find a full orchestra everytime you need to practice! ;P