Well, that's one of the things I'm sorting out by reading all the excellent replies to my original question. It seems some plastics have this messy brew, while others don't. Some of questionable health effect, some not.

I have noticed my Camelback 2L, which I just broke down and tried for the first time this summer, for day hikes, imparts a plastic flavor, more than I expected.

As for titanium, this adds yet another dimension. I have the MSR titanium cook set, very expensive, took me a few years to build up, but now that I have it, I love it. I rather hoped my titanium buying days were over. I've seen one of the titanium bottles of which you speak. I need to think about this. Looks like a sweet conveyor of bourbon, but not water.