Thanks for writing in. I'd be curious to know how the Malte Fischer biography changed your Mahler experience. While it's the best single book biography out there, I'm also a little skeptical of its constant negative tone regarding Mahler's legendary moodiness and social awkwardness. I think it's a tad exaggerated, especially after rereading Norman Lebrecht's "Mahler Remembered".
Some of Benjamin Zander's Mahler is pretty darn good. Some of it is a bit micro-managed (M4). I particularly like his M3, M5 and M9. Zander realized that he had created a patched-up 'train wreck' out of the first movement of M3, so he went back and recorded it again in one take. I'm glad he did because it's really very good.
My only complaints about Zander's M3 is that the offstage posthorn solo is a tad too distant, and Lili Paasikivi isn't ideal for the fourth movement (a tad too light sounding). Beyond that, I really like it.
Zander's M9 doesn't have the greatest sound by any means, but it's an 'honest' live recording. I'm hoping that at some point, Linn Records and the Philharmonia will agree to record M7 and M8 with him. There was a 'pirate' going around of a live Zander/Boston Phil. M8 that, as I recall, was really very good. Maybe he could someday get that released to Youtube, or some such place.