Just joined the forum; I love the show. The archives are great - really passes the time while commuting.
I've been brewing for about 6 years; mostly extract. Moved to all-grain about 2 years ago. Struggled with it for a while, then heard about RIMS. I'm an engineer by trade, so this appealed to me. I put together a custom RIMS setup and fired it up for the first time about 3 weeks ago. Mash efficiency on the first try was 82%, so I'm pretty happy about that. Next session is tomorrow...
Here in Northern Illinois, we have really hard water. I have an RO system, but the water comes out of it at a pH of 7.6, so I usually cut that by going 50-50 with RO and distilled water, unless my grain bill has a lot of dark malt.