I used this on a trip to hot, humid Thailand in hotels where insects and the cleanliness of bedding were a concern.
I wanted light weight and low heat. The silk-only bag was indeed light. The material and construction were of nice quality, but not the design was not the most convenient (not terrible, either). The mummy bag shape was fine, but there was no slit on the side. This was less convenient for entry and exit. Also kind of inhibited spreading your arms out while sleeping. Some might prefer this for the sake of protection from bugs. (Once I got in, I didn't feel claustrophobic). The lack of a slit also increased the warmth of the sack a little bit. My friend's sack had a neat feature on its hood/head portion; it had a fold-over piece of fabric on the hood that would secure the sack to your pillow. Mine just had a flat flap that laid over the pillow, which I usually managed to ball up by morning.