Is it permanently rooted? Or does it revert you if the TV decides to upgrade itself? Intentionally never upgraded my firmware, but it did it automatically once despite me not approving it.
Rooting is "permanent" until you factory reset the TV which returns it back to stock. This is handy if, say, you've got a warranty claim and don't want rooting used against you.
A number of people have reported that root sticks across firmware upgrades but I don't think anyone should count on that always working. You never know if a new release might find a way to disable root.