Basically good, as it's simply pressurized air.
The problem: the air going out is very cold and looks wet.
But read this:
If you know any physics, you'll know that pressurized air going out to unpressurised state, then it will get cold (it's how any cooling device will work, like AS or refrigerator). There is nothing you can do about this. For me, the most surprising thing is how wet the air looks like. I don't know if it's a normal effect, of the surrounding air that get condensed, or if the manufactured air is too wet. I'd like to hear from anyone who could compare it with an other product.
As a result I was worried of putting water in my computer. It really looks like you're spraying freezing water on your fragile computer components. Once I started the computer shortly after, and it was all right.
Still, I highly advice to take your time and wait for the air to warm up time to time. Do not use it too much continuously. On the label it's written that too much cold can damage your computer!
Note that if it's very cold, it means that the inside pressure is pretty high, which means that you have more air for the same money...…più