[HoosierBrew]

I see many references to RO (Revers Osmosis?).  What about distilled water?

Distilled would work perfectly fine if you build your water up with water salts like a lot of brewers here do. But it's usually more than 2 or 3 times the price of RO water. I can get RO from store machines for $0.39/gallon. RO isn't completely free of calcium and salts like distilled but it's very close and is a good base to build up from.

[hopfenundmalz]

Distilled is fine, just more expensive for marginally better water (IMO). I can get distilled with 1ppm TDS for $0.50/gal or RO with 8ppm (10 guaranteed) for $0.25/gal

Exactly my take on it.