Be careful
You all need to realize this does turn thermal throttling OFF. It is not off by default, switching it to "On" disables throttling. That's what the option does, it turns on not throttling. Make sense? Here's what I did to test.
Download CPU-Z from the play store and Antutu. With the switch set to "off: by default, run Antutu. While that's stress testing your CPU, open CPU-Z and check the current CPU frequency. 1.5-1.7ghz, maybe 2.0. However, turn the switch to the "On" position and do the same thing, you'll notice the CPU runs at its full 2.46 Ghz during the test.
One thing that doesn't make sense to me though, is while the phone throttles the CPU to 1.5Ghz, the temps are actually higher than they were at 2.46, but that may have been a coincidence. Thermal throttling on, (default) had the temps around 38 degrees Celsius, while thermal throttling off (set to the On position) reported 36 degrees. The phone felt hotter too while it was throttling. It's possible that while it throttles, the battery heats up while it's using more hardware resources, but that doesn't make a whole lot of sense. Their thermal throttling system seems poorly optimized, which is why I am going to turn it off and hope my phone doesn't burst into flames.
That being said, I did notice a little performance increase when opening apps and multitasking. It's there, not a placebo (well not completely), I tested it multiple times. But be cautious about what you are doing to your phone. I know the G2 guys have had good luck with this for a while now, but we are running a slightly different SoC than they are.