The different acids is in question too (at least with me). I have heard you need more phosphoric because it's weaker. I've also heard that phosphoric doesn't really lend a flavor component which is good. You need less lactic acid but I have heard that you shouldn't use more than 1ml per gallon of water used otherwise you'll go over the flavor threshold and start altering the flavor of the beer (for better or worse... some say that a little lactic acid SNAP is good). I filter first and then add CaCl/CaSO4 and acid before I start heating my strike water. I would agree that if you have a number in your water that is out-of-whack and/or very high compared to everything else, dilution would be the way to go. I have 138ppm of bicarb on my water which I thought was a lot until Martin told me that was a manageable number. Some people have 400+ ppm of bicarb so I envision lots of "water lugging" on brewday.
I think in something like a saison a little lactic snap is good. in others things maybe not.