Perfect for Florida
I love lightweight luxuries, and so far have only found 3 that have made the cut: a flask containing 20 year-old scotch, a Thermarest camp chair, and the Cocoon silk liner.
This is perfect for Florida, where we do 90% of our outings. In the coldest weather in January, it's does seem to add 10 degrees, and makes our tropical 35F sleeping bags quite comfortable. When it's warm, you just crawl in and lie on top of your sleeping bag. It keeps the damp off, but it's very cool and breathable. It has dramatically improved the quality of our sleep while camping.
My wife takes it on airplanes, just to wrap herself in it. It's perfect.
It weights almost nothing and fits in a stuff sack the size of your fist. This is our 2nd full season, and it's holding up well. My only regret is that we did not try this sooner.
It's a good value for the money
This bag liner seems to be well made. It comfortable. It's light and compact. Some bag liners claim they will add an extra 10 degrees to a sleeping bag. I don't believe this liner will bring a lot of extra warmth as light as it is, but that's not why I bought it. I bought it to separate me from my bag to keep my sleeping bag clean longer. It's perfect for that.
This liner is plenty long with an extension at the top for a pillow, or just your head.
I would recommend this product again. Actually, I did and a friend of mine bought one too.
This is the first silk liner I own, so can't speak to the comparison to the similar products from other brands, but definitely is way better than the cotton liner I previously own. This liner is very light and can be packed small. Initially I thought the size runs large, but quickly realized that the extra length can cover my head during the night when the air is freezingly cold. It feels warm and comfortable, keeps my bag clean. Very impressed by all the nice things I experienced so far.
On our very first camping trip the temperature was in the 20's. My son and I have 35 deg rating sleeping bag and this liner give us the additional warmth we needed. We had a great first night sleep. It washes well, easy to pack and weighs close to nothing. Since then we bring it to every camping or oversea trip. In the summer, we just slip into it and sleep on top of the sleeping pad. It's one of our best buys and I won't go anywhere without it.
I bought this for 2 reasons:  it's a nice and lightweight yet still adds some additional warmth to your sleeping bag and  it will allow me to keep my sleeping bag far cleaner from body oils, dirt, ... The cocoon liner does both very well and a very fair price. It would be a bit nicer if it had an opening along one side to make getting in and out of the liner easier but it wasn't a huge drawback for me.
Just as described.
So far this product is just as described. It is very lightweight and packs down tiny. Stitching seems strong, I will be interested to see how much warmth this adds as I find the ten degree claim to be a little bold for such a thin product. (although my silk long johns are miracle products so maybe it will) I will be using it this springbreak in Canyonlands National Park so I will update this review once I have experience with the product.
I bought this choosing between polyester and silk. Apparently the only downside of silk is the static. I used this in the Sawtooths in Idaho last weekend with lows in the 40s. I brought this liner and my 32F down bag. I slept in this with my down bag half unzipped and was very comfortable every night in a tshirt and boxers. I highly recommend the silk because it's the lightest, warmest, most compact, and you can wash it after every trip.
It does the job.
It definitely seems to add warmth to my sleeping bag. It is long enough that I can wrap it over my head; this helps when it gets really cold. I'm 6'2". Unfortunately, it is not as wide as my sleeping bag and my elbows feel constricted. The drawstring probably has uses, but I'm considering cutting it off because it just gets wrapped around my head. When packing I stuff it inside my sleeping bag, so its relative bulk makes it almost disappear.
Great liner, used for AT hike
I took this liner on my recent AT hike both for use in warm weather by itself and to keep my $400 sleeping bag from getting really overly funky. This liner was great. Took a beating, absorbed the dirt, was great in hot weather, and washed and dried nicely with little or no special care even in unpredictable hostel washers! It was a great deal at $20 less than competing brands. Highly recommended.
I purchased this as a liner for my sleeping bag I am taking to Philmont. I used it just by itself on a hot Arkansas summer evening and it was perfect. Best decision I made this year to buy this product even if it doesn't work for Philmont.
I camp on hot summer nights more than I go to Philmont. I am sure it will do the job in Philmont NM also.