I thru-hiked in 2003 and started out in full blown hiking boots. By the time I reached Franklin, NC (105 miles in), my feet were in bad shape and covered in blisters. I picked up a pair of ventilators at the outfitter there and and it changed my entire hike. No breaking in required. The blisters went away and the ventilators provided plenty of support for all AT terrains. I doubt they will last the entire trail. By the time I reached Delaware Water Gap, they needed to be replaced. But I think it's safe to say you should be able to get at least 1100 miles out of a pair. I had a lot of rain my year which definitely contributed to the wear and tear (it rained everyday while in Virginia!). The only downside is that they are low tops, so you won't have ankle support, but that shouldn't bother you if you have strong/flexible ankles and are used to hiking in lows/chacos. Don't even bother trying to waterproof them. They will soak through during your first downpour, but they dry out quickly while hiking. I've done several long distance hikes since the AT and I've always worn ventilators. Great value, durability and comfort. Good luck on your hike. It will be the best time of your life. Ponyboy PS Always have one pair of dry socks. It's the best feeling to be able to put them on at the end of a long, wet day of hiking.