I like the way those look, and the standard mouth is potentially very useful. I'm familiar with their cord lock gizmos and it is feasible to NOT cinch down the little set screw on the chocker block so one can fairly readily slide it open to remove the tethered cap from the bottle.

I'm thinking more along the lines of the vehicle water stash in wintertime than backpacking with one, though. Hmmm - think I'll order a couple when they are back in stock.

Thanks for the tip!

Tom