Hi Jeremy,
Mine has worked out great. I've hauled it easily over pretty rough terrain to places that I would have never gotten to if I had to carry my stuff (more than 5 feet from my car

). It is quite functional as is but now that I've used it for a while, I can see few changes that I plan to make.
As I mentioned, it was a bit of a mistake to think that I should leave the camera at the top of the pod while hauling it. While convenient and it does work fine over shorter distances, it is not the most efficient set up for the longer treks that I have discovered are possible with the thing. I plan to add a good, rigid way to support and protect the camera, especially the ground glass, in a lower position, as close to the axle as possible.
The other place I've noticed that my original design is less than optimum was in placing the axle directly beneath the bottom cross member. I think it would be much more stable with better weight distribution if the axle were placed up next to it, lowering the center of gravity and putting it in a more balanced, supportive position while being tilted and hauled . I put a quick drawing in the non-gallery to illustrate what I mean: (there was a url link here which no longer exists)
If you get a chance, check out these wheels that I ran across on the 'net:
http://www.beachcartsusa.com/buywheels.htm Total overkill and way too expensive unless you plan to regularly haul heavy equipment for longer distances over rugged terrain, but wow!, they would be the ultimate dream wheels for this project.
When you get yours put together, make sure you post a shot of it. I'm interested to see how it is adapted and improved by others.
-Neal