Actually I think the bigger guys are keeping their 9.5 Slalom sails up until it's so windy the race is abandoned at around 30knts. I can hold onto an 8.6 up until then.
If you're on an RXS (with a 9.5) you don't have a choice. ...and women have to use the 8.5.
...and no doubt this is all miniature compared to Formula.
So I suppose thats how far sail design has come.
...Oh McGain he wouldn't do that again...