I actually have the Logitech Alto. It's a great stylized accessory, and yes it does well at ventilating the machine.
However cheap it is not. At a little over $50 at Newegg, it's really just two pieces of plastic that slide together with a built in USB hub. On the plus side, it really is well designed (half my office stuff is Logitech), great synthetic grip so the notebook won't slide around, and really ups the "it" feature if your trying to go sophisticated.
I chose it mainly because as I researched the "coolers" out there, most of them were over-priced as well - I mean, a plastic plate with two cheap 80mm fans in it? Those don't even lift the notebook that much and would probably make quite a bit of noise.