Never fished on the Crooked River, but have on many rivers on the Western side of Oregon. Trout really are everywhere around there. I remember catching Cutts in what only looked like little puddles of streams. Bows are mainly what I caught, although a seven mile hike from the McKenzie pass will put you into some higher-elevation lakes that team with Browns.
As for the transition from #10 to #4: I did it the other way around. I liken it to driving the two vehicles I have. I drive a full size Chevy 4X4, but sometimes I have to drive my wife's Honda Accord. I just have to remember to soften up my steering as well as my accelerator.
The biggest thing I have to overcome while in Oregon is convincing myself that I am no less a man for having someone else pump gas in my truck (it's the law
Take care and have fun in the sales-tax-free state.