Hi PT,
The Maderna is one of my current favorites along with Sinopoli's Dresden 9. Can't think of two more different performances. Maderna's is surprisingly warm, passionate, even wild with, I think, terrific playing from the BBCSO. Given Maderna's history, I was expecting a fairly detached and maybe a little colder vibe but it sure ain't that. I can see lots of folks here taking issue with some of Maderna's tempos especially in the last movement when he puts the brakes on for a few seconds. But certainly one of the most interesting and for me enjoyable Mahler 9's around. And considering the age and that this is a live performance, I quite like the sound quality--up front, good dynamics, full, rich sounding if a little coarse here and there. Personally, I'd take this 9th over that of Chailly, for example, and several others who might offer the most technically accurate of readings but frankly bore me to no end. With Mahler, especially the 9th, I should feel something. Maybe not a first choice if coming to this symphony for the first time but worth having in my opinion.
The Sinopoli is far broader and I believe one of the longest on record but as others have noted, it doesn't seem that way. Sinopoli is a hit and miss conductor for me but strikes gold here. I suspect that is partly due to the Staatskapelle Dresden were perfectly in sync with his vision. Sometimes you can hear a conductor trying to get his vision or whatever you want to call it (hey, I'm no musician) across but the orchestra is simply not up to it. You may not like this particular interpretation but like the Maderna you can't deny that the execution is pretty good.
Just my 2 cents
cheers
paul