I like Hugh's advice on fishing two groups from the top and bottom and backtracking out to the trail to end the day. If you or any of your group had experience on the shoe then I'd say jump on it. It's not that bad but its long. If you didn't have an idea of how to pace yourselves you could get in a pickle by running out of light. That terrain is semi-rugged but with the lack of light you may as well be in the Alaskan wilderness.
Come back next June and hike/fish it lightly with a buddy to get the feel for it, one day. Otherwise, I recommend a hearty guide.
Use a wading staff anywhere on the river. You'll thank me later.