I don't like plastic-bottled water either - it's bad for the environment - but I always go for the still bottled water when I order it at restaurants. The bubbles (CO2) I feel aren't particularly good for you.

Yes, the US and other regulations for tap water are more stringent then for bottled water, but those regulations are concerned with things like ensuring that there is enough poison in the water to kill micro-organisms that may be breeding there - not at ensuring that you get the best possible drinking water. In Switzerland they seem to prefer to use Ozone rather then Chlorinate the tap water, which is better, but the the ozone does make the water a strong oxidant - ie aging, so bottled mineral water might be better from that perspective even in Switzerland.

Water from many of the fountains in Switzerrland is untreated mineral water, filling your bottle with that would be a great option.