I have read so many blogs out there discussing and preparing you for VCAP5-DCD. For VCAP5-DCA I did not make any preparation except doing some tasks in my home lab as I have appeared for the BETA exam and passed it.
These blogs are no doubt not to be under rated or such for those who are getting ready as they add more value of course. Now this is not some kind of judgement about which blog is good/bad but actually the nature of content which brought me to a position where I can just suggest to read them/go through while preparing for the exams. So don't go and compare one to another. All the information available through blog posts by our community members are equally important and valuable in their own stance. To add to that this is not some kind of competition where there is a winner or the 1st rank will be given, but simply the Quality of the Content which matters.
But to me one blog just came on the surface while I was looking at the content for VCAP5-DCD
This blog site is maintained by our 3 Engineers of VMware, Jarrett, Joe and Karim. I have personally work with them on numerous occasions and the stuff they have put on the blog is top notch. They have blended the information from everywhere possible to make the flow lot smoother while you are reading. The best thing is to have the links ready for further reading if one needs to dig deeper in a subject. They have also written for VCAP5-DCA so you can check that out too.
Recently @ForbesGuthrie passed his VCAP5-DCD and he mentioned in his Tweet that he used this blog for the preparation. So this is one of the use cases I would say :-) while recommending this site.
Now I have not meet him yet but know him as he was one of the writers of VMware vSphere Design 4 book which help you preparing for VCAP-DCD Version 4. Now most of the content you can definitely use for Version 5 as well as far as the design methodologies and principles are concerned.
One day I was researching for some specific issue and then found about the www.thefoglite.com. This is another Top recommendation for VCAP5-DCA by Ethan Rowe (@rowe_ethan)
Now at the same time I don't want to miss a chance to give the credits to @JoshCoen (Blogpost) and @jaslanger (Blogpost) for their respective contributions for VCAP5-DCA.
Hopefully this will help you in preparing for both VCAPs along with other resources out there which may includes various blog sites, videos, online sessions etc. etc.
Good Luck to all going for VCDX !!!!!