Ok, ever since I heard about the ExFog system I had to try it out. (Thank you @dr-lynne for making a post about it, thus bringing it into my orbit!)
So here's my review:
Firstly I should point out that the ExFog was listed as out of stock on their website, so I had to purchase one from Amazon for about 65usd, so keep that in mind going forward.
Secondly, I have not done rigorous testing. I have only worn it around my house and not outside in the summer heat. I did to a quick workout to work up a bit of a sweat and heavy breathing, but that still wouldn't account for outdoor humidity.
That being said, I do really like the ExFog. It's pretty small, so it's easy to hide; very quiet, any amount of background noise will drown out the sound of the fan; and not too complicated to set up and use.
As you can see the tubes hide against the ski mask extremely well. You can barely even see them from the front! The size of the machine is just right to hide under the hat, and it comes with three different ways to attatch it to your person. It has a headlight like strap that is designed to make the machine sit at the back of your head. It also comes with a loose bit of Velcro that you can stick onto whatever you want to attach to; I chose this option to attach mine to the top of my ski mask. The third option is...
Well it's certainly something. (I double checked the parts list and that said it's a T band, but honestly I have no clue how this is supposed to attach to anything). But never the less, multiple attachment options are always good.
As I stated previously, this thing is very quiet. Obviously I can hear it pretty well, seeing as it is literally attached to the top of my head, but the hustle and bustle of a local con or renfest will completely drown it out.
Setup was incredibly simple. All you have to do is snap on one of the custom manifolds (where the aquarium tubing attaches to the machine), shove the tubing on, cut it to your desired length, and then repeat for the other air nozzle on the other side, and you're ready to go!
All in all, this thing seems to work great! Although I haven't tested it outside in a humid environment, it has been exemplary in it's duty to remove and prevent fog. I will have to put it through more tests, but so far it's great. However the 65 dollar price tag can be a little steep.