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I have the podium pad for my MBA and it works great on the desktop. It not only helps with the heat dissipation, but brings your screen to a more ergonomic height (so you don't have to hunch over and stare down). However, there is no lateral support on the podium pad, and is probably not designed to be used on the lap. If you frequently use your laptop on your lap you may want to consider the other stand.
 
Don't bother with a stand unless you are using a separate keyboard and mouse. Most stands are only meant to raise the display to a comfortable height.

Also, if you slouch, the display might be too high up on a stand ;)
 
I personally like the Rain mStand, but it is only suitable for use with an external keyboard and mouse.
 
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