Wraet on 21 November 2013
A lower temperature case indicates the cooling solution is evacuating the heat more efficiently. The higher temperature during gaming, and lower fan noise would seem to me to be the result of the fan running slower.
The XB1 could reduce the temperature, but at a cost to noise. How much each metric would change is unknown at this time, so it's hard to predict how each system would compare for a similar temperature.
