The first time I used it I wanted to see if it made a difference in the acid requirement difference I was seeing in Beersmith3 and Brunwater. Both programs account for the adjustment but again there's about a .20 pH difference with BS3 left wanting more acid when BW says we're at 5.4. My pH meter agrees with BW 99% of the time.
As for my continued use, I had it to use and I'm just kind of enjoying the idea that I can use naturally acidulated malt in the grain bill without measureing and dosing with liquid acid. I still add it to the sparge water however. Whenever I have the need to be at the LHBS I'll probably get some but won't make a special trip if I have acid on hand.
Besides, if I use it in my lagers I can say they're reinheitsgebot compliant. @brew_cat