Revisiting the Abbado/Fleming M4, I can clearly see the points made by each of those who posted on this subject.
Barry is right about Fleming sounding better on the Berg, but I think most of this is because we are so accustomed to the soloist sounding more around the usual sounds of a boy soprano (and isn't that the way Mahler intended it?
Then again, Todd found after revisiting it, that the mature female voice, as is done beautifully here by Renee Fleming, gives us a fresh look at M4. It takes a little time getting used to it, but like hearing a new point of view, it can make you think again about your own beliefs.
Likewise Bluesbreaker questions putting Berg on the same disc with Mahler. Although Mahler and Berg shared many similarities, the Berg songs would be more at home with the dissonances of M10. It's probably just a matter of putting 2 Fleming performances together.
As Todd says, give the Abbado/Fleming M4 a revisiting or two. It can grow on you. It's "different," but as we all know, different is not necessarily wrong.
--John H