I have spent all my adult life in regular briefs but I keep hearing about chaffing of the thighs on long hikes. I've been backpacking for 40 years but not the daily grind of a thru hike. I doubt there is any scientific data but just trying to get a feel if boxer briefs are an absolute necessity and if so 6" vs 9"? Also would like to hear from those that completed the trail in briefs. Obviously I can switch along the trail if necessary. Thanks so much for any input. This forum is awesome!