I also have Stanley stainless steel coffee mug & water bottle for backpacking/ski touring. They have been built bomber for a 101 years. I would rather pay a little more for a Stanley flask vs. a cheaper one because I know it'll hold up.
Last thing I want to have so-so flask backpacking in the Teton/Yellowstone region have a slight leak (I've seen it happen with cheaper flasks) & whisky scent gets over your tent, sleeping bag or anything else. That is a smell bears like. I don't know about you, but I don't want to be a enchilada for a bear in my sleeping and/or tent at night.