Get on it while you can. Its a rare and endangered run, especially at these levels. Head up to Dilverthorne now for a kick in the ass run in a beautiful setting. Its also got a very easy shuttle suitable for hitchiking. You may be lucky to run it at 600 cfs in the future.
Be prepared for cold water - its the kind of run where a thermos of hot chocolate or tea would be nice to have along. Watch out for wood, you can scout Boulder Creek Rapid from the road, don't miss the takeout or you're in for a swift flatwater float through private property (its technical rock-dodging but still Class I at lower levels).
Nothing in the world is more yielding and gentle than water. Yet it has no equal for conquering the resistant and tough. The flexible can overcome the unbending; the soft can overcome the hard. - Lao Tse