In salt water sr77 surface browns very quickly (well within an hour or two), INFI just doesn't over that time scale. The rest of your observations seem pretty reasonable.

I'd suggest corrosion resistance wise it's INFI then a huge gap(!) then sr77 then sr101. INFI is pretty much stainless steel- the best stainless steel out there! Factoring in price and handle design (res-C protects the black coat which stops the tang rusting) the DF will be the chopper to beat, or even compete with..