I've heard the Stenz M3, and I would give it about 8.5 stars out of 10. The scherzo and finale are terrific. Stenz really 'went' for the scherzo, as he brought out all of the humor and irony behind the strange woodwind noises, as well as from Mahler's rhythms. The offstage trumpet work is really good, if also a bit close in perspective (which I prefer to being too distant). The climax of the long brass chorale in the finale - a real 'touchstone' for me - is done superbly well, with Stenz really drawing out the trombones at the final cymbal crash.
By the way, the coda to the scherzo is also done really well, with its alternating double cymbal crashes and double tam-tam strokes (the tam-tam answering the cymbals, basically).
There are really only two things that would keep me from giving this a full 10. First, I'm a tad underwhelmed by Stenz's first movement. He takes the two long 'happy marches' (in major) a bit quicker than I would have expected from him. The trombone solo isn't terribly distinguished, and I was a tad underwhelmed by most of the 'southern storm' fantasy section that caps the development section. That said, Stenz does an outstanding job of delineating the horn parts from the trumpet ones in the final bars of the coda (usually the horns just get covered over).
The other shortcoming, for me, is that the mezzo just isn't all that great. She isn't 'bad', mind you, but neither is she all that great in comparison to the competition. Some of the 'hinaufziehen' effects from the oboe and cor anglais (English horn) sounded a tad labored to me as well. Maybe they just needed to sound a bit farther back.
All in all, I guess I'm just a tad underwhelmed because I feel so spoiled with the excellent Honeck/PSO M3, as well as a 'burn job' that I own that was taken from a hi-rez download of the Alan Gilbert/NYPO M3. Both of those are truly hard to beat.