Why do you save your LB?

[Themis]

Whenever is most appropriate, strategically. Anyone that just LBs to LB when it has a better time or place is quick to get ousted.

This is really why it exists. Of course, if you are geared enough to clear the content with little issues (perhaps you run with the same group) then you can use your LB more liberally. But for new encounters and new groups, saving the LB can help the group turn the battle around in your favour.