I only made it through the first 3 movements yesterday. What I've heard so far is excellent. I do wish van Zweden would have divided his violins. Thomas Rolfs also gives one of the best posthorn solos I have ever heard. It just sounds right, to me. Alessi is also a bit more 'tame' in his solos, at least compared to his other recordings, but his sound is so pure, dark and huge it always works for me.
Personally, I find this recording to be very different than Gilbert or Honeck. Van Zweden comes across as much more Wunderhorn, very lyrical and rhythmically incisive. Honeck and Gilbert are more unleashed and direct, at least to me. They are very different approaches to my ears. Maybe more a question of how you like your Mahler 3 cooked.
Looking forward to finishing it off later this evening.