Hi
You can manually assign clients to a site server to ensure they talk to the site server in their subnet
we currently don't do that as we have some site servers that only cover one subnet but we also have some site servers that have many subnets in their site and with 6000+ clients I really don't want to manually assign.
However we run the "reset task server" task as a policy weekly as stated previously and with the setting "connect to server with best bandwidth" enabled it works for us. Rarely see any issues with wrong task servers on clients.
we also cloned the task server settings policy and assigned it to only the NS with Max clients set to 100
and then excluded the NS from the original policy, this ensures the NS handles few clients, keeps it working nice and smooth
HTH C