Poor new hire retention because management (at least on the legacy Harris sites) is not super great. They are nice people, but many of the Group Leaders are doing that in addition to their higher level/expertise topic position, so less oversight unless you are on the same project team with team. Also for a lot of people, if you become an expert in something, you get pigeon-holed into that position and/or become too busy to teach/help others to reduce your workload and help develop new people.