Yes, I chose the Stenz box due to the fact that they are regular CD's, and because of the price. Some cd players get confused by sacd hybrids. I feel that Stenz is more consistent over the entire cycle. Nott is more 'hit and miss', to my ears. Sound quality is generally better with Nott. I can't comment on the sacd layers.
For Stenz, I currently possess "Des Knaben Wunderhorn", M4, M7 and M8. All of those are good, if not great. Stenz is consistently on the fast side, but he has the best finale to M7 I've yet to hear (with a very good Nachtmusik II preceding it). He also has the very best ending to M8 I've yet to hear as well.
That said, the ending of Nott's M8 is nearly as good and has a better sounding organ. With Nott, I have M2, M4 (good soprano), M7 and M8. I did own Nott's M6 for a while, but a couple of 'interpretive' things about it led me to discard it. Namely, the tempi weren't varied enough between the opening march and the second subject; the so-called "Alma" theme. And second, the brief 'false victory parade' towards the end of the finale was too soft in the horns and percussion, thus rendering it too 'impressionistic' for my liking. By the way, I love the Simone Young/Hamburger Philharmoniker M6 on Oehms. It has an awesome finale.
I've kept Nott's M2 because it's one of the few where you can really hear the series of tam-tam strokes (7 in total) at the climax of the long march section in the finale. It does bother me that there are no extra tracks in his finale, because I often times do skip the soft choral parts (pretty but dull), just to save on time.
I did own Nott's M9, which is really quite good. But I already had too many two-disc versions of M9, and sold it off once I received the single disc Haitink/BRSO M9. I could have easily lived with the Nott M9, but I already had various Bernstein and Karajan versions, plus Dudamel/DG for the gorgeous playing of the L.A. Phil. I also have a live Ozawa/BSO M9, although the Bernstein/BSO beats them all.
In regards to Ivan Fischer/Channel Classics, I've got their M2 and M4 (both are excellent). M1 is also very good, but I'm picking up the Nezet-Seguin/BRSO one on plain cd. Fisher's M6 and M9 are just OK, while his M5 is a complete dud (in my book). It's interesting that C.C. has delayed or cancelled issuing an M7 with Fischer.
As far as complete box sets go, I currently have just the Boulez/DG. I sold off my Bertini box, but probably should have kept it. The Stenz will be a nice addition.