We never back up the workstations.
Until last year, they were still running on 256MB or 512MB of RAM, at which point I got them all to over 1GB. Most of them are on their original 20GB and 40GB hard drives.
All of our users also have administrative rights to the machines, many of them are software developers but even administrative staff have full access to their machines. Internet is wide open, nothing blocked, and these are daily use machines.
These machines are mostly hands-off when it comes to administration, I'm the only system administrator at a company of 100 employees.