My suspicion is that they're not useful at all. Once I bought such a cooler pad, and placed a 2011 13" MacBook on it. Then I benchmarked it (i.e. max out the CP

My suspicion is that they're not useful at all. Once I bought such a cooler pad, and placed a 2011 13" MacBook on it. Then I benchmarked it (i.e. max out the CPU), and measured the sensor "CPU Near". I could not measure a difference between the cooler pad on or off. I can't remember the brand of the cooler pad, but it had two 10 cm fans.