Great Bottle - With Necessary Modifications
I originally bought two of the white 1-Liter bottles. I bought them specifically because they mate right to the MSR WaterWorks and MiniWorks filters that I own.
The problem is that they leaked every time I used them - I thought it was a faulty lid and o-ring at first, but discovered that the culprit was the seam between the plastic threads at the top of the bottle, and where this cap piece mates with the body of the bottle itself. (not at the very top of the opening, but inside the bottle)
Once this was identified, I took a fingertip bead of clear silicone sealant and ran a quick swipe around the seam that can be felt at the inside top of the bottle. Let the silicone cure for at least 24-hours with the cap off. This completely cured the problem, and I've been very happy with them since!