Is this a sensible architecture?

I'm currently planning a shift in our use of LDAP to incorporate mirror mode masters for the sake of high availability. The plan is to hide a mirror mode master pair behind a virtual IP using "sorry server" fail-over, such that the primary mirror server takes 100% of the load when it's up and responsive, with fall-back to the secondary mirror server when the primary is down. In this way, the virtual IP presents a "virtual master" to the outside world, and the plan is for *all* outside LDAP interaction with the masters to happen over this single virtual IP.

There will be other "slave" servers which replicate the master (to distribute read-only load), and the plan is for them to syncrepl from the master virtual IP. I gather that a possible alternative to this arrangement is to have the "slave" servers act as syncrepl consumers to *both* masters simultaneously, via their real IP addresses. If this is indeed a valid configuration, does it convey any advantages? The single "virtual master" approach seems architecturally simpler, but is it considered robust by those in the know?