Now that I've spent a bit of time with this new Fischer recording, I can only echo what Russel said above. It is magnificent. Utterly musical, and connected. At times it is an orgy of color, texture and sound. Almost expressionistic.
The 2nd violins are captured wonderfully, they speak so clearly and in turn, so does Mahlers polyphony. Channel Classics has really outdone themselves with this recording. The dynamic range is very large, so you may want to pump the volume a bit higher.
There is a lot to like, I think. From the way the bassoons play the opening of the Landler, Ivan's amazing balances, or the damned rude trombones in the Scherzo. It's a powerful recording. One thing that has made me think when going through this recording, is that Fischer doesn't over emphasize many of the 'Mahlerisms' that other conductors do. At the very start of the work, the 2nd violin line, enters at the same volume as everything. As part of the music. Not in the way that phrase is often made so prominent. There is a lot of this through out the recording. Nothing is milked, nothing is brought to the fore, it's all just there, part of the music.
Excellent recording, would recommend.