So Vince if I read your comment correctly, multi-user file-gdb performance between two 'nix machines over NFS should operate close to optimal, but anything involving Windows will have problems? (including 'nix and Samba/CIFS?) ...which pretty much means anything involving Arcmap is trouble. Can you put a number on how many ArcGIS Desktop clients are involved when Microsoft networking starts becoming problematic?
The background for my question is that we've been using a file-gdb central store for our department for sometime and are contemplating moving to an RDBMS store, primarily to take advantage of gdb replication to district offices, secondarily for true topology etc. We've also been experiencing decaying performance issues over a number of months and are wondering if multi-user file-gdb is at root. Staying with a file-gdb store is attractive because we don't have any dedicated SysAdmins or DBA's around to build, tune and maintain an RDBMS, but in the end performance could be the deciding factor. (So cross our fingers and hope a spousal "yes dear" install of ArcGIS Server and Postgres is enough.)
Centrally we have 6 to 10 active daily use ArcGIS Desktop users, 2 to 3 data editors (but this happens rarely, once a week perhaps), 25-50 readers, currently using ArcReader but looking to migrate to web maps (served from a local ArcGIS server).
thanks in advance for your thoughts.