Yes, Ray's and Stark Bar now has a water menu of twenty different still and sparkling waters, complete with their own water sommelier, Martin Riese. When I was invited to a water tasting there, I was both tickled and curious. A "water menu" seems excessive, but I was curious if I can really taste the differences between different brands. I mean, I knew there was a difference because I never really liked Voss but have always loved Fiji, but I wanted to see if it really makes a big enough difference.
The water menu itself is pretty impressive and beautiful, with the mineral contents and flavor profiles of each water listed next to a beautiful photograph. So, the short answer to my question was YES, I can certainly taste the differences. Voss has a low TDS (6 mg of sodium, 1 mg of magnesium, and 5 mg of calcium) and has a little bitterness/sharpness at the end. Martin suggests that Voss would go better with salads, while Fiji would be better for desserts.
After the tasting, I think Fiji is still my favorite still water! Fiji's aquifer is hundreds of feet below the edges of a rainforest and the water that goes in there had gone through layers of volcanic rock, creating a natural filtration process. Fiji has a slightly higher TDS (18 mg of sodium, 15 mg magnesium, and 18 mg calcium) and it has a softer, almost "buttery" (as far as water can be buttery) mouthfeel to it.
I also discovered a sparkling water I liked, Badoit, from the Loire region of France. It has tiny bubbles that you'd see in a fine champagne and still tastes light even though the TDS is significantly higher than that of Fiji.