Can anyone share the advantages of using SDP CMDB over ServiceNow CMDB + Discovery module?

As of today, SDP CMDB is not yet mature enough that we can use this to manage nearly 7,000+ assets.

We want to store information of the following on the CMDB and get the relationship between these IT assets and it's relationship to an IT service:

* Windows Server

* Linux Server

* Windows Desktop

* Windows Laptops

* Routers

* Cisco IP Phones