I attended last night's performance of M9 as performed by Simon Rattle and the Berlin Philharmonic which was this season's opening night. As the three regular performances of this symphony in October will be recorded and thereafter released by EMI, I'd like to give you some hints what to expect.
Well, Rattle's is one of those M9s that will leave you shattered, exhausted, and probably deeply moved. Even though there were some odd tempo choices in the inner movements that one might not agree with (he was for example very fast with that short "glimpse of heaven" passage in the Rondo), his overall approach seemed extremely well thought-out and consistent till the very last bar. This is an M9 as dark and heavy as it gets, often times very slow and probably comparable in style to Chailly / RCO, Kobayashi / JPO (but with way better playing by the BPO), Abbado / BPO (Mahlerfeest '95), Bernstein / BPO, Sinopoli / Dresden, or MTT / SFS. It's one of those "old world" interventionist M9s that milks the music for every drop of emotion, that doesn't shy away from the most extreme outcries (some of the climaxes were so forceful it almost hurt), and that somehow seems to see the end of a whole world, a whole universe (rather than "just" that of one individual life, or of a certain symphonic tradition) in this work.
If you like your M9 to be more in the "modern" and aggressive way of say Barenboim / Staatskapelle or Ancerl / CPO, then you might find Rattle's way with this work overtly emotional and drawn out. But if you're in for a Mahler Ninth as grim, heavy, brooding, tortured and violent as it gets, I'd say you may really look forward to this one if EMI gets it right.