I have 2 chasis of 6509 configured in VSS.
Both are configured as per the guideline of cisco recommendations (SSO, NSF, mac-add synchronization)
My all servers are dual NIC with teaming configuration, one NIC per switch.
Whenever I power down the active switch standby switch takeover & become active but sametime there are connectivity lost to servers for around 35 sec i.e. the switchover is taking 35 sec of time.
But as per my understanding SSO & NSF should take care of that