So I got my eyex yesterday. And it works great! Never had TIR, but have a homemade ghetto-TIR I have been using with variable success. It took me about three to four hours to get the eyex to work, because apparently there is next to no support for ASMedia XHCI controllers. I would recommend anyone thinking to get this to check if their USB3.0-ports are compatible with the eyex hardware.
As for the experience of using it while playing DCS:World. A Vjoy virtual joystick is registering where on the screen you are looking and sends the inputs to DCS. Only four planes is supported out of the box. Without checking, I would think it's an easy job to add new ones using the same Vjoy-settings.
The eye-tracking itself really do work when it works. And the ability to follow a target with your eyes as you fly by felt really natural. The newest software has options to toggle on/of the device, push to enable, push to disable and re-center.
It does take some getting used to, and I do see some limitations compared to TIR, but I do also see some possibilities the TIR does not have, and never will. In the beginning I was moving my head around to make the eyex try to pick up my inputs, but i quickly got used to it. And unlike TIR, you do not have to sit there straight as a log. You can move around a little, and the eyex will still be able to see where you see.
If you are a fan of FUTURETECH and want to try something amazing, I would really recommend it. With the 30% discount going around its absolutely worth it. If you are not sure what USB-drivers you are running, don't like to fiddle around to get things to work, I would wait a little longer.