Yeah, it was the opening that sold me. I could just see myself on a chilly evening dangling precariously over a rock, holding my hands in ice-cold water, getting my jacket cuffs wet, while trying to coax the water into the opening of a Sawyer bottle.

Frankly, I think the PUR (Katahdin) Hiker is the best of all, except for the weight. You just plop the inlet into the water and pump. And it has two pre-screens (one inside wrapped around the filter cartridge.)