Water taste can be very subjective. Some people have blind spots when it comes to detecting flavours in food but you would think that water should not present any problems. However, this is not always the case.
In a water tasting, some time ago, connoisseurs of wine tasting tried many different waters. Second position after Evian was tap water. Now, at the time, there was some hint of unfair advantage for the tap water because it had been slightly chilled.
It is true that temperature of the water is very important in appreciation of the taste and this parameter needs to be constant in any side-by-side comparison. The total mineral content and type of minerals present also exert a profound effect on taste. I must admit that my favourite is San Pellegrino and this has a huge mineral content. Evian, on the other hand, is fairly low on TDS.
Iron content exhibits a strong influence on the taste giving a noticeably bitter after-taste. Bicarbonate also gives a very characteristic chalky taste, although food connoisseurs will tell you that this is a preferred taste in water for the accompaniment of food. In some bottling plants I have seen the taste-test for ozonated water being done immediately after taking a sample from the line. The panel of tasters actually have been trained to ignore the taste of ozone in determining the taste of the water. They certainly will not suffer from bad breath problems!