ThrottleStop should have the Set Multiplier value set to 28T. The T stands for Turbo since your CPU requires Intel Turbo Boost to use that multiplier when a single core is active. Post a screen shot or two while testing. It sounds like you are starting to figure out this problem.
Low power CPUs spend most of their idle time in one of the deep low power C States like C6. When in this state, you don't have to worry about what the multiplier is. In C6, the CPU drops the voltage and power consumption for that core to virtually zero so a high or low multiplier doesn't make any difference. Some people have a hard time understanding this concept. Here's some light reading about why a high multiplier is best.
Power Optimazation - A Reality Check
http://www.cs.berkeley.edu/~krioukov/realityCheck.pdf
Thanks for the helpful paper.
Changing the power level from 0 to 1 doesn't seem to be having any effect and somehow I can't change it to Level 2
Here are some screenshots.
