Anybody have experience with thermal intake manifold gaskets?

[Rustys14]

Like the title says, I was wondering if anybody has any experience with thermal intake manifold gaskets. Here is an example of what I'm talking about 91 98 Nissan 240sx KA24DE Heat Shielding High Performance Intake Manifold Gasket | eBay

Obviously the advertised 10hp and 12ftlbs gains are bullshit but they are supposed to be reusable. I don't really care too much about the power aspect but I am intrigued by the fact that I can reuse it since I do take the intake manifold off every now and then. All of the research I have done gives mixed reviews (mostly from Honda forums). Some people say they are great and others say they don't seal properly.

The gasket is cheap and I am getting ready to put a new motor together so I was considering using one but first I would like to hear from anybody who has experience with them. More specifically did it seal properly and where you able to reuse it? I would hate to have to deal with a mega vacuum leak because of a crappy gimmicky product.