The TDVCam is 2 camcorders inside a plastic case with some circuitry so you only have to press one button to turn the unit on and record. I really didn't get into the unit more than that since it is 'still in development'.
The TDVisor I tested was 800x600. The higher resolution models are scheduled for 4th quarter this year. Ethan led me through some demos of their 'AlterSpace', and a racing game. In AlterSpace you can roam around and hop into other mini games or watch movies in 3d. I was playing 3d pong where you were positioned directly behind the paddle on one side. Pretty cool. You could put some wicked spin on the ball.
At 800x600 I found the picture crystal clear. No ghosting or crosstalk or anything like that. There was very slight circular optic artifacts that I didn't even notice until Ethan said something about them and that they are working on their own optics to help minimize or eliminate them. To me they were slight enough to not have any weight in my decision to purchase or not. Something that had a little more weight was that I could not see the 4 corners of the display. I believe this was due to my bigger than average aquiline nose not allowing the visor to sit closer to my head. Even though I regarded this as a negative for me, it still was not a major enough thing to sway my decision to purchase or not. As previously stated, the picture was crystal clear with great brightness and no unsightly 3D'ish problems I've seen with other 3D solutions.
The visor weighs in at a mere 6 ounces. To me, this was very light. I was there for about an hour and had no sickness or headaches or etc from the unit. One issue I did have was the ski band was a little small for my head (yes, I'm a big guy!

One thing I loved about the unit is my ability to actually read text very clearly. Something very cool if you are looking at getting some privacy while working on something proprietary or whatever. Each screen operates at 85 Hz. I believe they are LCOS type displays. There was absolutely no shutter that I could detect, and 60 Hz monitors drive me crazy.
As for audio, there was a jack in the visor but I don't believe it was wired to anything. Ethan said it shouldn't be difficult to add that functionality. As for head tracking that is on there list of things to do, but there is no date for it to be available. I will probably be getting some more reflective tape for my TrackIR system and rigging that up. While playing games in 3D I found that moving your head was pretty disorientating because the view didn't change. It was something that kinda took me be surprise.
The system current requires 1 vga and 1 dvi output. Support for others is planned (like 2 dvi outputs). These are connected to a cable that combines the outputs into one cable and goes into a 'black box'. This box does something and the signal is output through 2 cables (which are twisted and sheathed together) to the visor. The black box allows for some processing of the video signal that I'm not exactly clear of. I believe Ethan said that he would like to eventually be able to load codecs into the box via a usb port. The box currently does not have one and would require taking the box apart and programming through some pins to change the operation.
They are planning on taking a look at the new nVidia driver this week. The nVidia stereo driver is the main method to allow 3d games on the visor. They do have a TDVCodec that allows for native 3d playback when video sources are encoded with it, but for games it's the nVidia driver. I believe the iZ3D driver coming out soon that can be purchased would be the method of choice for games on my system, since I have an ATI card. I would guess that it would be the setup of choice for many being that nVidia's support is sort of narrow right now. Maybe with their testing they will find it works out of the box. We will see.
After my experience with the TDVisor it was an easy choice for me to pre-order one. The image quality and the comfort of the visor were major pluses in my book. The cost is justified to me in that they are not pricing it so that they lose money and it will allow for better things to be developed in the future. I filled out the pre-order form on their site. Ethan said someone would contact me to secure funds. Once the funds are secured the TDVision hardware gurus ( they hate being called elves

I encourage anyone else that is interested and in the Chicago land area to demo the system as well. I was going to originally wait for the higher resolution solutions before purchasing but I've seen that I can have an awesome experience with their current offering. The other thing to consider is the fourth quarter is a goal, and not a 'for sure'. Plus with my system, anything higher than 800x600 for games with two outputs would probably just get me irritated at the slowness. I can enjoy 3d now!
Hope you find this review helpful! I will try to answer any questions. Please feel free to correct any of my statements.