Graham,
This does look a bit more practical for locations where you have a fairly good surface to roll over. I like the bigger pneumatic tires, versus the rollerblade wheels as are used on many smaller cases, though they are very good for those devices.
This sort of harkened to a long thread on LL that started out with the "needs" for location shooters. There was a description of the "cart of rocks" for the tethered tech one may need. Your cart of goodies shows that there may be just as much stuff to haul around for set-up. Really not that different from any DSLR stuff either, as the majority of things in your cart are lighting related, for the most part. (My portable studio stuff is just as bulky, even with all the camera stuff fitting into one smaller roller bag also.)
This looks great for open/street locations, or places with lifts, if indoors.
David,
I looked at those Wheeleez things in your link before also, and can see their utility on the beach and in some other softer terrane settings, but Graham's cart looks more practical for firmer surfaces for sure. Guess some folks really may need both kinds at times....just what we love....more stuff to accumulate ;-)
LJ