We ran this a couple of years ago at about 1800 cfs, from Northgate to Bennet Peak. Here's a bit of what I recall:
Northgate to 6-mile gap is fast and continuous. It culminates in a half-mile stretch with big waves and holes. It flips unwary rafts - regularly.
That said, it's a truly beautiful stretch of canyon.
The stretch below 6-mile gap mellows out a lot. It's still fast and continuous, but only Class 2. There are several lovely campsites along this stretch (for about the next 10 miles or so).
After that, you're in and out of small canyons alternating with ranch land. Get a map that shows public/private land, or camp at the developed campsites.
The shuttle back to Bennet Peak is looonnnggggg, though the roads weren't bad. It's better to continue downstream to Saratoga or I recall there's a campground upstrean of there on the west side, close to the highway, on an island(?). We didn't go that far, but next time I would .
Get good maps from the forest service, that show public/private land.
It's a great trip.