caramba. the chloramine is supposed to be more neutral in flavor.
but let me explain a couple things about flavor variation.
first of all, 85% of sf water comes from hetch hetchy reservoir, which is filled entirely by snowmelt from the northern half of yosemite national park. count this as a great blessing (most americans get their water from cruddy rivers (mississipi, sacramento/san joaquin delta) or groundwater wells).
the remaining 15% comes from local watersheds around sunol (south of pleasanton) and crystal springs (between 280 and skyline on the peninsula).
at various times, your water may have a different mixture of those sources, accounting for a possible flavor variation (the sunol reservoirs are more subject to algae blooms).
also, in the wake of the quake and fire of 1906, city reservoirs were oversized to provide generous fire flows. that and flow variations within the various city reservoirs can mean your water is fresher at some times than others. but another benefit of chloramine is that it is stable and long-lasting.
so for the most part, the water is better now than ever before, and is indistinguishable from bottled waters in both biochemical and aesthetic criteria. in fact, bottled waters sit in shelves, pantries, and car trunks for much longer than ours ever sits in pipes.
so go ahead, we'll take the pepsi challenge.
also note, most peninsula and some south bay municipalities get some or all of their water from us.