Design Degrees: Masters vs. PhD

http://www.aiga.org/content.cfm/is-there-a-doctor-of-design-in-the-house

debating the value(s) of a masters vs PhD degree and then also that a degree in design, especially big D design is a professional degree (like Design Management's MPS from Pratt). So it's less about the academic than the professional application. I'm not sure how I feel about this assessment. I think she's right that PhD is more about having an ultimate question that needs to be answered and so much more in-depth research in many more fields and perspectives is required. For me the question is: does that alone make you a better 'big D' design professional or academic?

Here's another viewpoint from my all-favorite Design Council: http://www.designcouncil.org.uk/en/Live-Issues/How-can-we-make-sure-designers-have-the-right-skills/

I like the comment that :
Too many designers forget that the focus of design is not self expression...' because as we all know that would be art, not design.

Does anyone who has applied their Masters or PhD degree at work (or to start a new business) feel that having one versus the other makes a difference in practice?