I used it for over a year on my frag tank. I would dose it from a reservoir with a dosing pump.
It works just like any other calcium hydroxide. There was some slightly discolored sediment after 6+ months in the container, but no ill effects on the tank.
In comparison to BRS kalk, it will function exactly the same. The brs is less "talky" and easier to scoop without it blowing into the air. Mixing wise they were about equal, with the brs mixing slightly more clear.