My wife and I have used one of these, trading off with other packs, for three or four years. We've drug it through a half dozen countries in the past few years and used it as primary luggage, not only as a daypack. It has served us very well, much better than other more expensive and more 'robust' packs. We also use for short backpacking trips.
Below is a short article I recently wrote about it; to see photos (they didn't come over) go to my website.
http://jamesmorganayres.com/living-lightly/
Patagonia Lightweight Travel Backpack
The Patagonia Lightweight Travel Backpack is offered as a pack that folds into its own pocket, takes up little room in your primary luggage and becomes useful when you arrive at your destination and unfold it. Then, voila, the tiny little pouch becomes your day bag, picnic bag, going to the beach bag. We have found it to be all that and more. We use it as a primary travel bag.
I say ‘we,’ but strictly speaking it’s ML’s bag. I only use it when she’s not looking, or when the load’s a bit too much for her. ML bought it over four years ago at the Patagonia store in Venice, CA. Since then we’ve carried it all over the world and used it far beyond its design envelope. This little backpack, sometimes heavily loaded, sometimes lightly, has been carried on and off dolmus, tuk tuks, jeeps, airplanes and trains; up and down mountains; through rain and snow and summer’s heat, without failing or even showing hints of failure. The stitching is as good as new. The fabric shows little sign of wear and is water resistant.
ML can pack a week’s worth of clothing and toiletries, her laptop, camera, a couple of paperback books, snacks and a water bottle in this gossamer wonder (the bag only weighs eleven ounces) and live out of it indefinitely. When she arrives at a destination, she dumps her clothing, laptop, and accessories in our room and uses it as a combination purse, day bag and grocery getter. The bag expands and contracts as needed. We have hauled two or three days worth of food from markets and bazaars to holiday apartments, rented rooms and camp sites in a dozen or so countries.
Yesterday at the local bazaar, she packed into it: a double bunch of two foot long leeks, a half kilo each of walnuts, cashews, dried apricots and goat cheese, a half dozen tangerines and tomatoes, a half kilo of onions, some potatoes and two loaves of flat bread. There was still had room for chocolate bars and a few other things, which ML picked up on the way home.
For a picnic with friends at the two thousand year old ruins of a Roman city, I carried it with four bottles of wine, two of water, a half kilo each of Brie and paté’, two baguettes, two pears, a bunch of arugula, a couple of tomatoes and a lemon, olive oil, paper plates, and forks – and my sweater and rain jacket. For camping ML can easily carry in it her sleeping bag and air mattress, food and water, and personal effects.
The only improvements I can think of for this pack (I used to design backpacks and luggage) would be to make the shoulder straps longer. They fit ML fine. They also fit medium sized fellows. I wear a size 48 jacket, and would like longer shoulder straps. Also, the elastic on the side pockets needs to be stronger; it has stretched out of shape. ML is planning to sew some stronger elastic over the worn out stuff.
In addition to the main compartment, there are two side pockets, one zippered pocket on the front, a back pocket into which slips a foam pad, and a top pocket for little stuff. The bag does in fact fold into the top pocket when it’s not in use, which is pretty much never.