I’ve been using an earlier version of thissince Sept of 2010 with no problems. I have the NC-1000B, and it’s no longer available. My laptop (my only computer) sits on it 24/7. I chose this one because it’s metal, which clearly is going to conduct heat away better than plastic. Also, it’s the same size as the computer, so the fan vents cover the entire underside of it. The pad has a couple of extra USB ports, which is nice. Anyhoo, read about it on amazon.
Just buy the cheapest one you can find. The actual benefits are minimal, and the most difference was achieved simply by having the laptop elevated so there was more room for air to circulate underneath; the fans make almost no difference.
^ This. The best option is to use a piece of wood or a small book to tilt up your laptop by about an inch or so. More air, better circulation. Also, have you cleaned your laptop’s fan?
For my old DVR, rather than using a fan, I went to Lowes and bought four of these door bumper things; you know, the things you put on a wall so the doorknob doesn’t punch into the drywall? I put one under each foot at the corners of my DVR to lift it up and allow for better air circulation. Never had overheating problems.