Couple of reviews on favorite blogs of mine:
Mark Berry, Boulezian
Finn Pollard, Where's Runnicles
I'm listening to it right now, and I'm with Finn. Yeah, the orchestra does sound glorious and there is some fine singing, but Barenboim's take on it is too glossy and polite for me, though he does indeed have a good grip on continuity. Just listen to the entry of the giants, which is around 42:00. Then compare with Solti. He's not my favorite Wagnerian, but note the accents and the slight sense of drag, as if the giants are so huge they are attached the earth and cannot move. Karajan is punchier than Barenboim, though smoother than Solti. I can't find Krauss on line; my recollection is that he is overwhelming in the section. See, also, as always, Furtwangler.
Update: WTF did they substitute for the anvils? A bunch of cowbells? Sheesh.