MyCloud or MyFritz as dyndns service

Hi All,
I just ordered a WD MyCloud EX2 Ultra NAS, for using as NAS and as a private Cloud server.

I have a Fritzbox, with an actice MyFritz connection to access from outside. (Like dyndns).
WD also predicts to use a similar service, called MyCloud.
I am wondering, which of these service I should use when installing the EX2 Ultra NAS…

@Cloud64 Look at this sub-forum.