"Finally, in the great Adagio that brings the symphony to a close, the picture snapped into focus; the heat of emotion remained, but the music coalesced into one long, glowing line."
Here is Alex Ross on Daniel Barenboim's last concerts. I think that I've discussed it here, but last October, a friend and I went to see Barenboim conduct Mahler's 5th. He later took the CSO to New York with the same piece. I had his 1997 (I think, but it is mid-90s) Teldec recording of a WDR performance with the same forces. In the intervening near-decade, his style changed. Sometimes for the better, sometimes for the worse. His Trauermarsch was grim then and grim now; however, he managed to follow the music and open up where it was needed.
However, and this is someone who loves Barenboim's Wagner, his problem is this: he doesn't know when to manage. He started as a pianist, an artist. A conductor has to manage as well as create. Sometimes, you have to stand back and, other times, you have get into the band and make them play as they must.
One wouldn't have to step back if he kept the fire lit all along the line.