I have gone through many cases of bottled water over the years, but am really working on carrying and using reusable water bottles. I actually have a few metal drinking bottles, all free or gifts. I do try to keep a few in the car. I tried to save and wash the plastic bottles and refill them. The life of a plastic drinking bottle is not long term. In my ongoing purge and clean out, I emptied and disposed of many plastic bottles. I filled up the recycling bin with them.
I have one case of bottled water, but it is a few years old, and don't know that I will drink it, but I am not sure. I think having some bottled water is good for a SHTF situation, but I am not rotating one case, so I probably wouldn't rotate more.
I have never been about reusing milk jugs, but the water has not been turned on at dog parks yet, has been off since last fall, so I need to take water when I take dogs. Many days, I am the only person taking water for a couple dozen dogs. People do take milk jugs that are cleaned out, but they leave them. After I had forgotten water one day, I decided I would grab all the jugs that were rolling around there that day, so I now have 7 gallon jugs of water in the car. I know they will eventually spring a leak, but in the mean time, I will use them.