It's too easy to give magical properties to your favorite sharpening stone especially if it is a little magical like the Lilly White Washita. If I had to own and use only one stone it would be the one. David Weaver, IIRC, used a Washita in a one stone and strop sharpening regime. Brian Holcomb can attest to the quality of his edges.

I have the pick of a number of systems and stones ranging from Diamond plates to high end JNats. For day to day sharpening of everything from pre-War Marples to #1 White Steel Japanese chisels I use a 3 stone, 4 step process. Grind (if needed) on a Med India, refine with a Washita, polish with a Hard (surgical black or translucent) Ark and a light strop on leather.

Truth be told, I could do a David Weaver and skip to hard Ark.

One caveat, I avoid A2 like the plague.

ken