John:
I agree with your overall enthusiasm for these two performances. Sonically, most of the MTT/SFSO releases are unsurpassed in terms of realistic "you are there" sound when in multi-channel SACD. I don't see myself returning to the cycle's M3 and M6 very often, and the M5 and M7 don't really make my first tier of favorites, but the M2, M4, and M9 all are first rate. I am a little bothered by one particular affectation by MTT's, though. You specifically mention his ritardando near the end of M2-3, which sounds completely unnatural to me. OTOH, it is SOOOOOO different, that I find myself anticipating it in other performances -- and being rather sadistically disappointed when it is not there. I like the first and final movements of the M2 quite a bit though. His finale features a phenomenal percussion crescendo before the march of the souls (and the march is great, too). His second movement is too slow for my taste, but that is a problem for me in my Bernstein/DG reference performance.
The M4 is on the slow side, so I was rather happy when the Macal was released as a faster SACD alternative. However, the playing on the MTT is gorgeous and I rather like his conducting. This may not be a first recommendation from me, but it is a recommended alternative. As for Laura Claycomb's singing in M4, I really like her voice and singing in this movement. Now, I do not want to argue with Barry's knowledge and ear for the music, but I just cannot hear what he is describing. To my (untrained) ear, her singing sounds like it is in rhythm with the music. I have listened to the relevant section and compared it to both Bernstein/Grist and Salonen/Hendricks (two of my favorites) and cannot hear any real difference -- excepting the Bernstein has a much faster tempo overall -- but I cannot discern any difference to the rhythm in the voices versus the music.