How did you measure the temperature reduction? I switched to Engine Ice last year and using a Scangauge I haven't seen a noticeable reduction in operating temperature. In over 100 degree ambient my R3T still runs at about 200 at cruise and in stop and go often hits 223 before the fan is able to pull it down to around 212-215.
I've tried stock fill, distilled water with Water Wetter, and now Engine Ice. None seem to be markedly different than the other.