Although we don't have a document that lists the advantages and disadvantages of an LDAP integration (it dependds
on the customer needs), it is true that with a non-AD environment you can add, delete, edit users without depending on AD administrators. However, if you like to have all the users concentrated and configured the same way in not just the CUCM, but CUC, and CUPS, then AD is a good choice and it will be easier for administration purposes. First of all, if you plan to use CUPS you need an AD integration as a requirement if you want to get all the features working.
The most important change is that users get synchronized with the LDAP server. Please consider that CallManager cannot have more than 5 LDAP queries activated or synchronization agreements available. Therefore, LDAP deployments with many OUs or containers can be an issue.
You can see how the synch works on the SRND below: