Another vote for them, although I am still pissed I didn’t get that shirtless, autographed horseback picture of Snyder when Kifaru fixed my duffle bag.
the compression strings are static and as Justin and others mentions above they compress your gear into a cylinder with a relatively fixed length. Most compression sacks that compress from the ends leave you with a roundish ball That you have to pack around. The kifaru sack once compressed slips down into the bottom of my pack and settles in more efficiently with all my sleep gear in it. I run a medium with a 20* synthetic bag almost all the time for backpacking and hunts. I am thinking about getting a bigger one or just another to compress my extra clothes as well.
only possible draw back (apart from not getting my picture, Aaron) is I have never tested water proof ness. My goto for clothing is sea to summit event dry sacks which are pretty waterproof. The kifaru is probably fine with light rain inside a pack but I wouldn’t take it for a swim. If dunking were a serious possibility (boat/canoe trip or propensity for being stupid) I might take some extra precautions to keep my bag dry.