I have both the Easton Stealth S17 in 7R and the 68K/70K in 6.5 D. The S17 is definitely very narrow and wide even in the R (I'd say Nexus D wide). The S17 are also slightly deeper than the 68K/70K.
I'd agree that the 68K/70K are wider in the fore foot than the previous generation Ribcors and definitely a much narrower heel.
Also, I saw some S17's and S12's on Sideline Swap from the Perani's store in Canda with limited sizes. Might be work taking a look