A great blog post on Mahler
Life With Mahler contains one of the best assessments of the film I've read thus far.
"Life without him is not living.
How can anyone live without Mahler? Standing at the cusp between the classical romanticism of Tchaikovsky and Schubert and the atonality of Stravinsky and Berg, he changed music as we know it. Whether through his beautiful songs or his massive symphonies, one’s understanding and appreciation of nature is raised an order of magnitude through listening to his works." Thomas Pindelski.