Hmmmm first time I've heard of this group...(but then again I don't keep track of anything) I suppose what they're doing is something I'm trying to figure out on my own on and off.
My read on it is that it's trying to bring everything together, MBTI type, a bit of enneagram, cognitive type, interaction styles etc. Not enough info to tell more though.
I'm a little cynical with their faq...
How do you know this? Who thought up this model?
This work has been intuitively perceived and systematically investigated. It has not been thought up. One could make an analogy to the system for describing plant life in families, genera, and species -- it is a descriptive system based on what actually exists in nature; it is not the only way of looking at the distinctions among plant life, but it has proven extremely useful.
Any model originates from a creator... otherwise it's not a model is it? The linnaeus classification system is not a model.

I'm a tad peeved at the way they're stretching the truth... but okay it's how you sell a product.
For example, mental-physical people as aloof, not caring; emotional-objective people as pushy, too quick; emotional-subjective people as soft, unfocused; physical-mental people as mechanical, uncaring; physical-emotional people as slow, too detailed.
mental-physical = NT, emotional-objective = subgroups of NFs, emotional-subjective = subgroup of IXFX, physical-mental = XSTP, physical-emotional = XSFX
The break down isn't very clear without a proper description.
What kind of research has been done?
The research has been qualitative and exploratory. There have been relatively few attempts to quantify our research because that is not the direction of our interest nor does the subject matter lend itself to quantification. The single most important piece of research has been the thousands of people who have participated in the self-identification process in seminars. Additionally, more than 400 videotaped research projects (from USA, Canada, Israel and Sweden) have been completed with infants, children or adults; one particular research piece has been videotaped over 150 times.
More rigorous research (non- social science) is planned within the next few years; this will follow-up on initial explorations in distinctions in metabolism and sound patterns between the personality dynamics.
They didn't objectively proved anything with that... I'm not sure why I feel like nit picking. It will not be an easy task to objectively verify the validity of their system.