| Thermal paste is highly conductive, ok it doesn'y match the properties of metals but you would be wrong to think it's an insulator.
In this case it's most likley that the better results were due to the fact that the nickle plate had been removed and the thermal paste was applied to the copper, which is a far better conductor than nikel. It also is'nt a completey flat surface, that last picture clearly shows fine scratches through the copper (although certainly smoother than before) |