First the easy questions:
"Why not mount it somewhere other than the visor?"
I wanted it mounted to an area that wouldn't cause me to have to cut the actual mask. Cutting up the mask could make it less protective. I also didn't want the fans where they were likely to take a direct hit. Mounting them vertically to the front means they would take a lot of shots.
"Does it tned to dry out your eyes?"
Absolutely not. Due to the low amount of air that actually makes it's way through the top and the high humidity inside the goggles...nothing like that occurs.
It has worked very well. Much better than the Vortex fan or no fan at all.
Problems I've run into:
One time my glasses fogged up real bad. Why? The fan is so quiet that I thought it was on and it wasn't.
There have been a few times in thick brush where the bundle on top of the mask was vulnerable to branches. It's more the mesh that I have on there than the wires...but it is something in the back of my mind I always have to worry about in thick brush.
The batteries will last a weekend or longer. The only time I've run them down is when I played at the monster game...played all day both days...left them on alot (again, they are so quiet you forget they are on) when I wasn't wearing it.
Other than that, it's worked great. I wish I could get it to provide more airflow...so that it had more of a cooling effect...but I don't want to start cutting into the top of the mask and risk having someone squeeze a paintball in there somehow and take out my eye.
Hope that helps!