Thank you good sir. I've been going back to th Berlin Phil./Mahler set recently. I still love the Dudamel/B.P.O. M3. I think if the name "Dudamel" weren't on there, more people would pay attention to it. I think Christiane Karg sounds really good on Y. Nezet-Seguin's perfectly acceptable M4 as well. For me, the only slight 'dud' is A. Nelsons M2, but I'm going to give that another shot. I've even warmed up to Petrenko's M6. Even though the sound quality is better, I just don't see the need for for me to get the Jansons/BRSO Mahler box (which also only has symphonies 1-9 as well [plus a pair useless rehearsal and jibber-jabber discs]). I find these Berlin ones musically more engaging.
If you look on E-bay, you can now get a box-set of Haitink's Mahler with the Berlin Phil. (Philips). As you know, he only recorded symphonies 1-7, two song cycles, and the 10th symphony Adagio. I wish somebody would issue his 1988 Mahler 8 from the Concertgebouw. That one can be viewed on Youtube (great sound, but darkly filmed). It wasn't part of the Kerstmatinee business, so it's never been offered with those.