I've tested both
947U w/ 92mm Tornado fan at 50% and
Dangerden Maze4 on same system. The difference between air temperature and CPU diode temperature for the 947U/92mm Tornado@50% was 24.9C. The difference in water temperature and CPU diode temperature for the Maze4 at 0.5GPM flow rate (a LOW value) was 16.5C. So for the water cooling setup to do worse than air, your water temperature would have to be ~8.5C over room temperature. That's certainly possible with smallish radiators and quiet fans. The fact that increasing airflow through the radiators did very little to temperatures is disturbing though. Makes me suspect a faulty CPU temp reading more than anything else...