Some Clarity on Sharepoint ACLs

Well, I finally got some info today from Microsoft that pointed me in the right direction. We've been struggling with the best approach for our team sites considering the many number of Sharepoint groups that we will have. The link below really cleared things up for me about how the ACLs work and confirmed my inclination to break the team sites into their own site collections primarily for these reasons:
Dedicated administration - Security is separate, so the site owners will only see the groups for their site and no need to break inheritance
· Individual quotas can be setup on site collections, not sub sites, so we can better manage the growth of the larger ones without affecting the smaller team sites
· Recycle bins can be setup for each site collections, so these can be managed individually.. If everyone shares a site collection, then they share the recycle bins storage size too.
· Site collections can be grouped into a single db, or split out for easier management, & backup restore if necessary..smaller team sites should be grouped together for optimal db performance- query paths are chosen based on data characteristics (small number or large sites / large number of small sites)

More Clarity on Sharepoint ACLs => http://blogs.msdn.com/jimmiet/archive/2009/06/06/acl-limitations.aspx