check out this pic; this is a zxl of course but I believe the new surflites rig similiarly...its blowing about 33--39 knotts, this sailor weighs about 185# and is on a JP FSW85... so he's sailing overpowered conditions for a 4.2 sail yet is still totally dialed in.. not sure if you can tell but the downhaul has the the leach wrinkled down between the 2&3 batton from the top..
http://wetsands.smugmug.com/gallery/3714816#213124423
on the other hand, check out this pic with the same conditions as the above pic.. this sailor weighed about 175# was on an old school gorge animal(heavy board) and looks like he was on a 3.2 --maybe 2.8 (???) older vintage surflite...notice how he doesn't really have much downhaul at all yet he was rippin fully powered and appears dialed in as well..
http://wetsands.smugmug.com/gallery/3714816#213129332