Have not listened to MTT, but read LOTS of reviews, both here and at sa-cd.net. A mixed bag....
What I love about Lenny is his total involvement with the music, and all the emotions and feelings he evokes. I mostly experience that he is conducting as Mahler might have. Music, for me, is a living reality, and therefore approaches and interpretations often change, just like so-called real life.
The "intellectuals" do not make it for me in Mahler, with their analytical and distant approach (e.g. Boulez, Chailly).
I listened to M2 yesterday afternoon (the DGG version from 2005 with NYPO), and realized two things. First, after not listening to Mahler for almost three years, it took some time for me to enter his soundscape, so to speak. Second, turning up the volume seemed to increase the SQ.
Also, these re-masters are better than the M9/BPO, which I listened to later in the evening.
I will try to borrow a copy of MTT M2, M3 or M6 on SACD, if possible. No sense purchasing same without an audition.
And as I wrote, the SQ on Fischer/BFO is incredible, but the interpretation in many parts left me wanting much, much more. Lenny provides exactly that.
Also, growing up in NYC and attending a number of his concerts, as well as watching his tv programs, interviews, and such, gave me a sense of knowing the man personally, and a great appreciation for his approach to music.