At the risk of being expelled from the forum, I will confess that I bought M9 with Haitink and the BRSO, a live recording, more than a year ago but hadn't gotten around to listening to it. I guess I just wasn't ready for another M9 obsession, until now.
This is a terrific performance. It is sharply characterized, the orchestral playing is first rate, and the recorded sound is excellent. Haitink divides his violin sections antiphonally, a huge benefit in Mahler and a practice I don't think I've ever heard from him before. One can always quibble--some would prefer more demonic intensity in the Rondo Burleske--but that is not Haitink's way. Overall it is an outstanding M9.
I find that often, live recordings are lacking in depth and definition in the bass, but that is not the case here. The sound is as good as anything I've ever heard, transparent from top to bottom. The audience is dead silent.
Mariss Jansons has built the BRSO into a superb orchestra. They played Shostakovich 7 here in Chicago a few months ago, a performance of unbelievable precision and virtuosity. In my most recent M7 survey, Janson's live recording went to the top of the list.
As I listen to M9, I've been particularly impressed with Alan Gilbert/Stockholm, Dohnanyi/Cleveland and Ozawa/BSO. Stenz is a strong performance, but as I mentioned in a previous thread, contrapuntal detail tends to be obscured, even at moderate dynamic markings, odd in a modern recording.
Finally, I'll mention one of my M9 acid tests: In the second movement, at the end of the last fast dance episode, the tempo has been accelerating into delirium, but at bar 529, the tempo abruptly shifts back to Tempo I, much slower. Coming up to the bar line, the horns play their four ascending sixteenth notes, and these are to be at the fast tempo, a typical Mahlerian joke. However, a number of conductors slow down early, ruining the effect. Masur/NY is particularly egregious example, sad because the performance is otherwise one of the best.