I don't know it as well as some people who live closer to it, but IMHO the best rides are from about 6-10,000 cfs.
10-15,000 cfs has some good waves.
Swam twice in one day at 9,000. Probably my favorite run ever. Once at Triple Bridges (fell off the front after getting smacked by a side wave), next run I fell off the back guiding through Tumbleweed and took a submarine ride. I wouldn't take younger kids above this flow.
Above 17-18,000cfs and its blown out. Not many waves, but big seamy eddy lines. Flipped my 13' raft in an eddy line below Fang once.
Below 6,000cfs, and its fun and splashy. The few holes are small.
Below 2,500 has some great drops.
It's 3,600 today. Great for kids.