I still carry the bags that came with the Sawyer as a backup (they don't weigh anything really) but I do like the wide flat opening on the CNOCK for collecting water. That's what originally drew me to the CNOCK.
I've also found it to be pretty resilient. I'm clumsy, on occasion, and have dropped the CNOCK bottle more than once and (knock on wood) still haven't punctured it.
one or more gifts or other benefits from the co-op.