You could setup your own dns servers obviously 18 years ago and in fact when starting out in the mid 90's that is exactly what we and many others did. (Criket Liu nutshell books from O'Reilly)
I use dyn as well as run several dns servers in different places 
My reason for not using this is that it's being offered by google and the obvious fear that they will decide one day to stop offering this, supporting it, or improving it. As I am experiencing now with google voice for example,
 Since the mid 90's actually learning from this book:
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