Also - can you elaborate? I always just thought they were S series, which meant Saber. Didn't know there was a differentiation.
I think it was Ernie Ball that had a model named Saber so they kicked up a little fuss about rights to the model name. Ibanez lost or conceded. Since then we have had the Ibanez "S" model line (S#) which is past that date, and was named Saber (#S). Colloquially they are all referred to as Sabers nonetheless. Post '92 you see a lot of S# models which greatly diverge from their fusion or do-all style catering roots which already made them somewhat unique compared to the RG, but still here and there with all manner of body and neck variations frequently blending them in directly with contemporaneous RG specs to an even greater degree. That's not especially relevant in this context, just a way of me implying that within the broad scope of those post '92 guitars which can vary a great deal in specification are genuinely unique guitars. Before that point it was pretty simple, a different looking RG. I definitely should have elaborated on that, I just meant to basically reiterate they are not all the same and the line has changed through the years, but mostly greatly after the abandoning of the Saber name. IIRC pre '92 (#S) guitars came in two model variations every year, with the only difference being the body and I believe a headstock reversal. Both had RG spec Wiz necks but entirely different bodies of course. Satriani's sig is very close to and came from a Saber in this pre-92 era.
Basically, the biggest changes to the Saber line have always been the bodies, but post 92 necks started changing as well occasionally. I'm not sure exactly what year that would be. I know the post 2010 models firsthand a lot better than 90s and 00s, because I did not prefer the models I did play during those decades personally. Even the S6527 has changed a ton through those years in so many ways, yet all are the same model name- which makes it entirely more confusing and the model is not alone in the suit of doing so.
@Ibanez Rules can probably correct me and definitely elaborate I'm betting. I'm stretching my insight at this point.