Having owned the Solti Rheingold for longer than I like to think about, I decided to buy this one to hear a different take.
The Good: 1) Overall excellent singing and characterization. John Tomlinson as Wotan was in fine voice for this performance. Overall the cast is quite fine. Tomlinson sounds tired in the Barenboim Siegfried, but not here. 2) Bayreuth sound - a bit reverberent, warm, enveloping. Sounds great! 3) Barenboim's tempos are well chosen. I haven't followed the recording with score in hand, but I don't hear the tempo instability that one reviewer complains about in his Bayreuth Walküre.
The Weak: 1) Solti had Kirsten Flagstad for Fricka! Barenboim didn't. His Fricka sings well enough, but she's not in the same class. 2) Live performances have stage noise; this one has quite a bit. I don't mind this, but if you like total silence behind the performance, then this recording isn't for you. 3) Solti had better anvils and hammers in the underworld. Bayreuth's sound tinny.
Overall it's a fine Rheingold. I like it.