I know that it gets a lot of attention here already, but I would add that BeerSmith has an interesting approach to water management. It has listings of the water mineral content from several major brewing cities (as well as a several major locations around the US), and allows you to enter the water for your own local aquifer if it isn't there already. It can then calculate the mineral additions needed to replicate the water for, say, Dublin, Ireland, when making a stout. It isn't the best approach, as it relies on the idea of duplicated an existing city's water rather than trying to optimize the water for the particular beer, but it does make matching historical styles quite easy.
Getting back to the original topic, I have used Five Star pH 5.2 Stabilizer in a number of brews, and while I haven't had any off flavors, I can't say it really helped much, either. I had picked it up in hopes of avoiding a lot more detailed work with the water chemistry, but I no longer think it is the magic bullet it is propounded to be. I am especially annoyed about it, because the last time I was buying brewing supplies, the LHBS owner advised me on the matter, claiming that if I was going to use the pH stabilizer anyway, then there was no point in getting the other mineral additives, as they would simply be overwhelmed by the stabilizer. It wasn't until later that it occurred to me that pH wasn't the only reason for adjusting the water chemistry. That is certainly what I will do in the future.
Sort of a pity, too, as Atlanta water is very soft, being primarily rainfall runoff; it is very low in pretty much every sort of mineral, and in fact is (assuming BeerSmith and the local water company are correct) nearly a match for Pilsen water. This means that it should take very easily to just about any sort of mineral additions, without having to bend over backwards to remove or mask anything.