Water Chemistry Modification?

I got my city water report and played with that cool chart in Palmer's How To Brew.

It turns out that my unmodified water is fairly ideal for exactly the kind of beers I brew most: beers with a large amount of base grain and some crystal type malts.

I know what to do for all base-grain beers like a pilsen. My question is mostly for very dark beers, where it apprears that I'd do well to raise my pH a little.

Do most of you AG brewers do any sort of water modification, or do you just RDWHAHB?

Anyone use Five Star Buffer 5.2? It claims to automatically stabilize mash pH at 5.2 regardless of grain bill or water chemistry. They claim it boosts efficiency.

Again, seems like it would be good for "typical" PAs and the like, but I think you want a higher pH for stouts and porters, right?

On my last mash I used 5.2 stabilizer. I did get an increase in efficiency, but it was the only mash I've done this for. Crush was the same as all my others and i jumped from 65-70% to almose 80%.

I'll keep you posted after my next couple mashes and see if it is consistent

Whats the ingredients in the 5.2 stabilizer?

I don't exactly whats in it, but I know on the package they are listed as "food grade buffers"