I haven't tried BG42 yet, but s30v isn't one of my favorite steels at all. It's still in the "very good" lot, but I hate sharpening it. I'm not sure what "exotic" means, but I don't think s30v is it.
Funny how the x42 description compares s30v to stuff the previous x42 wasn't even made out of! They don't mention BG42 in their little tribute. Better than 440c? Who the %$&# asked?
It's not really what I would call high hardness either at 59rc. That's more like "normal" for good stuff. Buck hardens their cheap base level steel to 58. What does SOG consider 62? Or are we still pretending BG42 doesn't exist?