If you are letting it rest and want the optimal experience, I don't let the meat drop below 175 before serving as it starts to dry up -- not horribly so, but that was a tip someone gave me a few years back that I noticed made a difference when serving right after cooking.

Obviously, this isn't the case for the leftover brisket (if there is any) that is used the next day (that night at midnight) for sandwiches. The leftover brisket will always be a little drier, but still can retain the great taste!