Should we add the dominoPerson objectClass to our users just for a couple of attributes?

This question has been nagging me for a while now. We know that if we want to provide presence awareness in WebSphere Portal for all authenticated users that we will likely need an attribute for that users' Sametime server. There are a number of attributes that we will likely need from the dominoPerson objectClass for our users in LDAP. So does it make sense to have all users inherit the dominoPerson objectClass or would it be better to add those specific Domino attributes to our custom objectClass for users?

One thing I noticed in testing was that our user objects have many attributes we probably wont use since they inherit the dominoPerson objectClass and I can see that many of these are redundant. Some of them already exist in the other objectClasses such as person or inetOrgPerson.