When I was there May '05 there was a couple who were really irate demanding a manager when they were told no walk ups were being accepted. A manager finally came out and I guess the man thought the louder he got the better chance he might have of getting in. Didn't happen though. The wife finally said they would just place an order to go. Again didn't happen--the manager said they didn't take take out orders. The man finally yelled "are you telling me all these people in line made reservations 90 days ago to eat here. Almost simultaneously almost every one in line yelled 'yes, now what part of no are you not getting'. The timing when everyone yelled yes was so perfect and so funny. Sorry, but the man was being so obnoxious and refusing to move out of line.
By the way last Sept and this past May they were also not taking any walkups. So yes I would definitely make an ADR.