Electric kilns with electronic controllers (such as the Skutt KilnMaster series) have a thermocouple which continuously measures the temperature, records it over time, and shuts off the kiln when the appropriate heat absorption has been met.  So if the ramping temperature is fast, the kiln will go to a higher temperature before it turns off than if the ramping temperature is slow (thus allowing the clay to absorb more heat along the way.)  The final temperature is most affected by the rate of temperature increase over the last 300 to 400 degrees of firing.

Note:  Think of the 0 in a cone number as meaning "minus".  So 06 is much cooler than 6 because it is like a "minus 6".