I haven't got around to taking the 5.x one, but the 4.x one was very good, I really enjoyed it.
With that said will this exam fully prepare you for the exam, no, however it will give you a really good understanding around the core concepts that the exam touches on along with some great design experience and best practices.
Doing the acutal design part is only half the battle on the DCD. The other half is trans-coding customers requirements, assumptions, risks, and constraints. Along with the the three fundamental design phases (Conceptual, Logical, Physical) and how to transition through these.
So if you where to break down the exam I would say its 50% design, 50% theory on the conceptions of design. So this course will defiantly help you with the design part.
So in conclusion:
- I believe the course is done well and will leave you with some new experiences and skills
- I believe this exam will help with the design, and compute parts that are on the DCD
- I'm not sure how much of the theoretical stuff they cover as far as the design phases go or risks, consumptions, or cover EVERYTHING that is on the blueprint ect. However if you do take it please report back on the forums and let us know 
However there is still some extra studying you should do prior to sitting the DCD exam. Many people take this course then write the DCD feeling they where ready for it and have a bad experience. So I would go into the course with design in mind, not with it being the be all end all to pass the DCD. I just want you to get the best experience out of it and be properly prepared if you write your DCD
If you have any other questions please let me know,
Also I have a DCD simulator at www.virtualtiers.net and there is a really good study group on google+ just search for VMware DCD