when dealing with large volumes of resources, a few things need to be improved:

1) dynagroups - ora...1000 item http://127.0.0.1/bugzilla/show_bug.cgi?id=2) recursive groups - first addition is fast, rest are dog slow after that (as well as removal)
3) resource browser - delete group with many resources in it

there could be others, but this is a start.