They might be sanded, but they'll still have ridges at the nodes. If they were sanded totally smooth, it would weaken their structural integrity.
Regardless, they will not be as straight as cedar, and you will likely have to straighten them using heat.
More work to turn into a good arrow. Will likely have to drill out the front end and glue in a small piece of dowel before tapering the point end to receive a point. Different procedure for trade and stone points, which I won't get into. May need to do the same before tapering the nock ends, or make self nocks out of hardwood inserts. Probably won't be able to find them spine and weight matched as closely as cedar.
All that being said, they make a very durable arrow that flies quite well. They're naturally tapered along the entire length of the arrow, which adds some FOC and contributes to good arrow flight. Tougher than POC in my opinion, but not indestructible.
I got some from a fella in the Kalispell area a few years ago. Can't remember his name Went by the handle of Fletcher the ? on this site. At the time, priced less than cedar and good quality. I see they're also being offered on the auction site now. I know nothing of their quality.