I haven't seen these, but have seen other pots with the same principles and think they are good. I think you are defeating the design somewhat by burying them, though, since roots won't be air pruned. However, if you are planning on using them mostly for plants with fibrous root systems, I don't know that such a pot design is necessary. Maybe you could surround the pots with a mulch inside of the whole to allow for the root pruning.
Here is a discussion on a citrus forum (where I met Joe Real, BTW)
http://citrus.forumup.org/viewtopic....&mforum=citrus