OS X Server file sharing slow to browse and users get wheel

I am currently having an issues on a couple OS X 10.10.2 servers where users are intermittently getting the wheel when trying to save a document to the server (Word, Excel, InDesign), sometime when opening folders, they take an excessively long time to list the files and folders (30s to 60s)

Users at two locations are both connected by smb3, most clients are also Yosemite, or Mavericks. 10-20 users. File permissions are simple, we have 2-3 users that people login as, with folder permissions set with user groups. Could multiple Macs all logging onto file sharing using the same username be an issue? We have about 10-15 users logging on as 1 user and a few others with more elevated privileges logging on as different users.

Anyone have any suggestions or similar experiences? Please let me know if I need to provide more detail.

Thanks.