Just did it yesterday. Ended up taking a 60m which was great for a 3-person team (one on each end and me in the middle).
Only pitched two of the sections above the notch (1st and 2nd not including an easy scramble between). Scrambled climbers left to the summit around the HUGE Mazama team taking forever on their fixed lines. No criticism of the climbers here, or their commitment to safety, just wish the non-profit organization would bring less people, or at least more experienced climbers on a route that is prone to bottlenecks.
Didn't rap off the first or second station; fairly easy down-climb, although a rap off the first sling would have been safer and probably quicker too.
After a total of two hours waiting for the Mazamas at the top of the first pitch, we rapped all the way down to the notch in ten minutes.
Met Rocky_Joe on the summit who brought a 30m as promised--nice guy by the way, and climbing with a quality team. The 30 seemed to work out just fine for the raps, as long as you're willing to down-climb the easiest part of the first pitch above the notch just like jfs1978 said. Joe, did your friends have any trouble rapping off the summit with that length by the way? Didn't look like it.
In hindsight a 30m would have been just fine for our level too, since the middle man could have self-belayed on a fixed line between the leader and 3rd man, but 60m was probably quicker for three guys on the ascent, which is important on a busy day.
All told, good times on the choss. Thanks for everybody's input on my original question, hope this info helps someone in the future.