All that I heard was true... I spent last week on the Payette system outside of Boise and there is amazing whitewater there! I highly recommend checking it out, whatever level boater you are.
I did the Carbarton run on the N Fork, above the sickness called the North Fork (16 miles of mostly class V). It was fun,pool drop wave-train class III with a couple of flatwater sections. But the flatwater was actually moving so it was a good float... plus I saw a bald eagle soaring over the river. Beautiful scenery, warm water, and several really good surf waves.
The Main was similar (downstream of the sickness) to Carbarton, maybe a little easier? and lots of fun. Camped over the weekend outside of Lowman on the South Fork at a secluded, paradise of a campsite along the upper reaches of the South Fork. The water there is emerald green! You can see straight through to the bottom. The water is rumored to be cold, but nothing for those of us used to CO water temps in May. Easy to get soft in Idaho I guess
We ran that section, referred to as Grandjean. Also class III, with some really nice hot springs at the end of the biggest rapid.
Stepped up to the Staircase run on the South Fork by Banks (where it joins the North to become the Main), which was really a blast. I was pretty wide-eyed though, so decided unfortunately to not run the Canyon section
-- which looks so beautiful -- but is supposed to be a step up from Staircase. Guess it's not going anywhere, and I plan on going back!
Thanks to Id725 and those who replied, you were right on. I did get Grant Amaral's guide and it did a good job with basic descriptions though I couldv'e done with less description of first D's of class III runs and more descriptions of individual rapids... we are all way too spoiled by the CRC guide!