I'm liking some aspects of the Vänskä M1 a lot, and some things are just a bit off to me. Here are some of my observations as a whole:
Pacing/conducting: weird. An average view of the first movement, and quite a fast second. A slowwwww third, and a broad finale too. There isn't any sort of arch here, it seems arbitrary. I think in terms of pacing the second movement works best (though it is quite fast). The third movement is just paced very strangely to me, and I don't think it works. If Vänskä did more with the klezmer episodes I think this movement would have succeeded. I still prefer the solo double bass in the opening. The finale coda is slow and hardly exciting, like Konsgaard mentioned. I really don't feel frenetic energy there, and I think that has to do with the deliberate tempo and static dynamics.
Sound quality: excellent for the most part, as expected. The string textures aren't as tight as the recordings of M5 and M2; the M2/I and M5/III and V have some of the best string clarity I've ever heard recorded in a Mahler symphony. The trumpets and brass in particular don't shine like a European orchestra (or even the SFSO or Pittsburgh), but they sound darkly hued, if that makes sense. I'm not great at describing strings or brass. As I found with the M5 recording, the crash cymbals also sound dark in timbre. I think those qualities fit the Fifth, but not so much the First here, a lighter and brighter symphony—for the first half at least. I don't know if that has anything to do with the cymbals used or the way this one was recorded. The bass end of the spectrum is fantastic. As I said before, the offstage trumpets in the first movement are phenomenally captured.
Performance: top-notch, as usual. I think that's a result of extreme drilling and refinement, however. Possibly editing too. I don't want to discredit the Minnesotans though because they really are excellent players. Essentially every orchestral detail is present.
If anything, the value I find in this recording is that it'd be a good one to follow along to the score with. Maybe not for tempi, but for studying the actual notes. I think that goes for all the Vänskä recordings so far.