MA Pete
Pattern Thin Convert!
Just from handling some R9 models, they seem to vary a bit depending on the particular run.
Not sure about the actual specs of each run, though, as I've never looked into it that deeply, so this is just going by feel.
Yes, R9 neck specs vary a lot. Depends on year for production R9's, and even within a designed spec for a year they vary a lot. About 4 years ago they reduced the size of the R9 neck, giving it narrower shoulders, similar to what PRS did with going from WF to Pattern, same nut width but narrower shoulders and thus a slightly smaller circumference. And then of course for these signature run R9's they very precisely measure the actual 59 being honored and match those specs, which I believe is the case for my Paul K and Joe B.
Both of my R9 necks are fairly significantly bigger than the Pattern Necks on my 2 MSC's. But not horribly so. I don't mind them. (What I feel the most is the larger fretboard radius, the board feels more "flat", and the smaller frets.)
Since we are on a PRS Forum here, I will say that I love the PRS Pattern neck combined with the smaller fretboard radius and the Jumbo frets. These Jumbos on the MSCs are squared off on the top to simulate some wear, and they feel great!
That is one of the things I love about the PRS Guitars, while of course they will vary from Guitar to Guitar, they are still MUCH more consistent than Gibson's. It gives me great comfort that when I spec a PRS Private Stock, I know I can count on loving the neck when it comes in. Buy an R9 sight unseen and you are rolling the dice re what you get for a neck. (A lot of dealers, like Mark's Guitar Loft, post very precise measurements of the necks for that reason.)
BTW I think my next PS will have a WF neck versus Pattern, just to have one of those in the mix again, those are my favorite two PRS neck Carves.