Listening all the way through these gives a pretty favorable impression. Obviously, you don't get to hear the endings to either part, which are THE POINT about the entire work. Regardless, Botha sounds great! He's got to be the best tenor doing Docktor Marianus these days. I wish they would move the women behind the orchestra during the gorgeous three "penitent women" passage. It's such beautiful accompaniment. Better yet, Mahler should have taped their mouths shut and had the singers hold up flash cards at that point. I've always thought that a music-minus-one Mahler 8th might be pretty cool.
At track 18, notice how de Billy acknowledges Mahler's "adagissimo" tempo marking, but in cut-time; the half note gets the beat. There has to be enough tempo so that there isn't huge amounts of space between each harp plunk, which only makes it sound like Anton Webern (Tilson-Thomas, he made it Adagissimo in 4/4). Nice rubato there too. All in all, I think this is going to be quite good. The men soloists sound particularly good. It's hard to tell about the sound from JPC's player - I had to keep turning it up. Coming from Vienna's Konzerthaus, it's going to sound a bit cavernous. But that's not a bad thing in Mahler 8 - better than sounding too congested at the endings to both parts.