I haven't used this on a backpacking trip yet, so this review is based on my initial impression. It is very lightweight, comfy and it is long enough, but the crew fits very close and is somewhat see through.  I plan on using this as part of my sleep system on the AT and will have to wear  something over this when modesty is needed; so even though the crew is very lightweight, I will have to add additional weight to my pack in order to cover this for when I'm staying in the shelter and for nightly bathroom breaks. If I had the option, I would give this 4 1/2 stars because I probably would have given it a five if it was not so form fitting and transparent, which might be just a personal preference because I'm a chubby girl  and like to be covered up. There are no complaints about shipping.