Access is designed for scale. The white paper Scalable Security Modeling with Microsoft Dynamics CRM 2015 at https://technet.microsoft.com/en-us/library/dn683914(v=crm.7).aspx highlights design considerations given different scenarios. The paper highlights that Access Teams are the preferred mechanism when users have in excess of a thousand team membership.

For a functionality comparison between Access Teams and Owner Teams, read the MSDN article at https://msdn.microsoft.com/en-us/library/dn481569.aspx.