If you are asking about the Piney River, north of Vail. I have a little bit of beta. There aren't a whole lot of people who have run it or run it frequently. I personally have only run the first two miles or so.
This could be a good season to run it. It reallly hasn't been run more than a couple of times (if that) since '95 or '96.
It's a long run. Get an early start. I started late in the day (noon) in '95 and realized at our pace it'd be easier and safer to walk back to the put-in rather than keep heading towards state bridge. Set up shuttle the night before and camp at the put in or stay in Vail, or try to find a shuttle driver willing to hang out at state bridge most of the day.
Lot's of wood in the run. It's in a wilderness area and also runs thru private land. It's hard to keep clean of wood. The road is snowed in during the low water spring months. To clean it out in the fall might be kinda futile as the winter would bring more deadfall. Also, seeing as there haven't been many runs and we've had low water over the last several seasons, i'm sure it's well restocked with lumber.
There are lots of mellow stretches in it, interspersed with steep continuous class IV+ to V sections (especially in the first couple miles) or vice versa. I hear that it gets somewhat easier toward the end of the run.
Try asking Gordon Banks, Dave Eckhardt or the Chaimberlains. I believe they ran it in '95 or '96.
I think it might be best to catch it on the way down after peak, in the hopes that high water flushes out all the timber and the snow has melted from the banks.
These are just my thoughts after seeing the top couple of miles. Of course it was quite a few years ago. Now my impressions of it might be different. It could very well be a great mission.
I'm thinking about it myself this season.