I ran it years ago (1995) by hiking 4 miles up the trail to the footbridge. It was running high, say between 1000 and 1500, and overall I'd give it a class III+ rating- big waves but few memorable rapids. There were a couple of times when we were coming downstream at a good clip & come around a corner to find a river wide tree, and we'd have to scramble to the sides. Definitely a danger there, because you're moving at 10-15 miles an hour through that canyon at those flows.
Given everything else that's flowing, I wouldn't call the stretch I did worth the effort. But then again, I think I was in a Pirouette S; maybe a spud boat would make the hike easier and the run more fun- if you want an adventure, go for it.
As far as putting in at Purg, the word was that the woodfest made it not worth it. Don't think that's changed, unless someone spent a good month hiking the creek with a chainsaw last fall.