I was considering picking up this stand for my uMBP: One thing that concerned me was having higher CPU temps with the lid closed. I read a thread a few days ago that said there is no CPU temp change between lid closed and lid opened. And after doing some of my own testing I now believe that information is FALSE. I use smcFanControl to control fan speed and monitor CPU temp. Before using smcFantControl to boost my fan speed to constantly run at 3,400RPM, my CPU temp was 10-20 degrees (celsius) higher, on average. As for the lid open vs. closed theory.... Setup: - 24" external monitor - wireless keyboard/mouse - Targus Chill Mat Apps running: Safari, Adium, iTunes, Mail, inDesign, illustrator Fan speed: set at constant 3,400 RPM's Time powered on with all apps running: 4 hours Ambient room temp: 72 degrees Fahrenheit Lid closed CPU Temp: 64 degrees Celsius Lid open: CPU temp: 43 degrees Celsius Take this info as you will. I just know that I will be using my MBP with the lid open from now on.