Hi,
I'm not aware of any best practice recomending that.
It is a good practice (at least for me) to use Storage DRS in vSphere as it provides the automatation desired for me in a cloud enviroment. Since now it is possible to mix sDRS and vCloud Director (it was not possible before), I guess this is only a good idea too!!!
I would be precaucios in things like SLAs that you have with your cloud tenants so Profile Driven Storage and affinity rules should be taken into account in order to have the vmdks in the appropiate kind of storage. For example, if your customer (external or internal) pays for a silver kind of storage, make sure that sDRS won't move that vmdks to a "gold" kind of storage and viceversa.
Regards,
elgreco81