Pumphouse to State Bridge is pretty much to first place people think of to float in the fall, which is why you'll have plenty of company doing it. If you would like an almost-as-pretty section with practically no one on it, think about floating the Colorado below State Bridge. Catamount to Burns is pretty and there's a ice campsite river right on it. Also about six miles below Burns is one of the nicest places to camp on the Colorado at Jack Flats, train noise is not an issue. From Burns south all the way to Dotsero the river is paralleled by the Colorado River Road, so bike shuttling is very possible. Also for a fee you can either camp at or get shuttled by staff at the Thomas Ranch (970-524-1440).
There is onerapid to take note of between Burns and Derby Junction, called either Rodeo or Landslide Rapid depending on who you ask. If you run it hard right it isn't too bad, but the flow will try to take you into the middle where there is a nasty pointed rock. (There's a Hyde dory in there right now that got stuck Saturday, which might there until next May). You can also put in below that rapid in Derby Junction for a smal fee, you can call Glenda at 970-653-4408 for more info.