I've got some of the heavier Nalgene bottles I've been using for 25-30 years. Mine have taken a real beating, but other than some slight discoloration they are as good as they were the day I got them. In the early years I disliked the odor they seemed to have, but for years now I've been storing them between outings with a few teaspoons of baking soda inside, which helps.
That said, I've learned that serious Appalachian Trail hikers (thru-hikers) are now largely using gatorade and other similar bottles. They have opted for them due to weight (they are an ounce-conscious bunch), but also because of Nalgene's supposed brittleness. Nothing like a 2,500 mile hike to give your gear a thorough workout.
You can learn a lot by reading some of the entries on trailjournal.com or on one of the Appalachian Trail message boards. If you want to know the potential problems with a particular type of stove at higher elevations, or how to stay warm in a hammock during the winter, or which boots can take a pounding, or how to get sufficient protein on the cheap, check out those boards.