Sg:

No argument there. No two rivers are the same. I also generally agree with your generalizations. If I'm limited to one setup on the Lower Hoh, while it does have a lot of sneaky lies that can only be reached effectively by nymphing, I'm packing a spey rod, a set of sink tips, and some big, bright flies. On the Sol Duc, while it does have some great swing water (especially lower down), I'll opt for a nymphing setup.

Thankfully, nobody forces me to opt for one or the other, so I bring 'em both (generally speaking, of course) for maximum coverage.