I'm always amazed at these discussions. The one thing that never seems to come up is what is the pH of your water to begin with. In most of the temperate regions of the US (and I assume the world) the pH of tap water will be slightly acidic to neutral (pH 6-7). Here is the desert SW, the water for the City of Albuquerque has a pH of 8, on the alkaline side. Using a water stop with an alkaline developer will just slow down the developer, not stop it quickly like it is supposed to.

Personally, I usually use a half strength mix of Kodak indicator stop. For certain developers, Diafine and DiXactol, I use water.