Jordan Roth from the Certification team at VMware has posted a couple of great articles about the VCAP6 Design exams on his blog The Cloud JAR.
These 2 specific articles give a great insight into the build and scoring of the VCAP6 Design exams that Jordan himself has worked on:
VCAP6 Design Tips, Tricks, and New Features
Scoring for VCAP6 Design Exams
I'd consider both articles to be "must reads" for anyone preparing for a VCAP6 Design certification - in any of the 4 solution tracks.