Hey, that's the problem with posting on P-wrx, you say something and then you get asked for evidence!
Ok fair question.

After a 2.5 conversion and bigger turbo, the original stock unit could not cope, the tuner had to reduce boost from mid range for safety. It was not possible to tune on the dyno, not enough cooling. After fitting the ProcessWest TMIC the power is now limited by the injectors - I still have the stock 440cc. Getting about 214kW atw, 6000rpm. So, no temp probe but I am satisfied it cools well.
My thoughts on the water spray are more subjective, 'seat of pants' told me it helped on the standard setup but I could not be sure there was any difference after the mods with the more effective PW tmic. Anyway, the nozzles did not fit well on the rubber shroud.