I can certainly sympathize with that feeling, as that's exactly how I feel about Haitink in other pieces. And I must concede, parts of that performance were magnificent. But I didn't feel as though that weight could be sustained all the way through the performance because Haitink seems to have a resolute refusal to inflect the piece. In certain Mahler pieces in which the form is more severely constructed (particularly the 4th and 6th) this somewhat extremist non-intervention will not matter as much - at least not for me. I really like Haitink's latest M4 and M6, mixed reviews or not. But I suppose for Mahler 9 I either like it uptempo or flexible, my favorites at this point are Abbado, Bernstein, Barbirolli, Kubelik and yes, Bruno Walter. (...though I make an exception for Riccardo Chailly)