I open the top vent all the way, and throttle with the lower vent.
One thing my brother did, and I copied, he marked his vent ring with percents of open. From closed to 100 percent. It's a great idea, because the way the one touch is it's hard to see closed, and the percent of open is not linear because of how the vent wings are.
By the way, you are going to love your new Performer.