[Zope] ZSyncer and ZEO

Does ZSyncer have any problem with Zope/ZEO systems? I have some anecdotal evidence of problems as we migrate to a multiheaded Zope/ZEO systems architecture. Is there any difficult using ZSyncer between a Zope and a Zope/ZEO combination. Are there problems syncing between Zope 2.6.X and Zope 2.7.X systems? All the systems run ZSyncer 0.5.1.