I like Zinman's cycle, in general, just for the reasons that Todd mentions. Zinman treats Mahler as good music, and not as a constant hysteria festival. I still argue that there's a "classical" form & structure to this work; more of a overriding concept than than anything else, really. Of course, this is a very different Mahler 6 than the Bernstein on DG. As strong and powerful as Bernstein/VPO are, I just find that Bernstein allows the finale to sprawl too much: it's well over 33 minutes. I also find him a tad too fast and driven in the first movement. Yes, Zinman is more restrained in the first movement. But notice how he allows the "Alma" theme to move forward, and not become bogged-down by an over-romanticized touch. Also pay attention to the two, very brief passages that I've mentioned previously: the very beginning of the development section (immediately after the second playing of the "Alma" theme), and the muted horns - which are quickly switched to open horns - just before the coda. These brief passages assure you that someone is clearly paying attention, and not just sleep-walking. If this performance doesn't grab someone, so be it. But it grabs me very much, and I've had a very long and personal association with this symphony - more than any other Mahler symphony, actually. That doesn't make me "right", but it does mean that I've considered these points very painstakingly.
By the way, John; as slow as Zinman's scherzo appears to be, both Haitink/CSO and Gielen are a full minute slower. Listen to how he makes a true, horror-show climax just before the tam-tam smash (and hence, the movement's subsequent melt-down).
Barry