I use it with my 15 '' MacBook Pro. The MacBook ever achieved in demanding programs, a CPU temperature of about 90 ° C, which is then discharged through the aluminum floor -> there's is nice and warm when you have the computer on your lap! The Lapdesk you can feel the heat anymore.
Although the 4 supplied rubber pads spoil something that good design, but keep the computer even with considerable skew of (what the two 1-star reviewers write about it slipping from Macbooks, I can not understand) and provide an additional few millimeters distance between laptop and Lapdesk what makes for a good air circulation.
The elevated position of the computer is also a boon for the neck muscles. If you turn the Lapdesk 180 degrees, you have either a relatively horizontal or an inclined working surface - depending on whether the work has his feet on the ground, or rather laying on the table ...
Conclusion: great product and the price really a must!
Addendum (8/2011):
I more than a year have the thing now practical in daily use, and it is still as stable, comfortable and white (!) As the first day. The upholstery has no millimeter subsided. The build quality is so absolutely first class!
Addendum (9/2013):
... And still in prime condition. Perhaps not quite as immaculate white - the material is stop but only plastic - but otherwise in a condition as the day - especially the upholstery. Am satisfied to the highest degree!