
My limited experience with the S-78/S-88 is that the camber is similar- the flex of the S-78 is stiffer. My limited experience was that the S-78 performed better on denser snow- the S-88 performed better on soft, fresh snow (similar to the Eon/XCD GT).
BUT- with both of these skis in your quiver, you'll be able to give us a much better test than I can!
And I agree with you- the S-112 is wide enough that I need a relatively rigid, burly boot to hold it on edge (at least on dense/hard snow, and very steep terrain).
That being said- the S-98 is still quite a ski. I can drive and telemark my Epochs with the Rossi BCX6- BUT only in soft, fresh snow. IME, the S-98 is easier to turn than the Epoch/10 th Mtn. This may allow you to push the soft boot boundaries with the S-98- further than I can with the Epoch. But this may also may be simply a matter of personal skill!
Regardless- having the narrower S-78/S-88 will allow you to restrict your use of the S-98 to the ideal conditions for your boot/binding.
You've got my favourite mtn binding- the 3-pin-cable! So versatile! Xcountry performance, plus downhill power.
I unfortunately have decided to maintain both 3-pin-cable and NNN-BC setups. I unfortunately have been happier with the performance of the NNN-BC versions of most light leather /composite Nordic boots- the BCX6 included.
Will be VERY interested in your experiences with the S-98 and the Rossi BCX675-3-pin-cable setup.