The tickets are sold an hour before curtain. There is a window to the right of the lobby entrance that sells SRO tickets. The line forms there and goes toward 8th.
I did it a week or so before the Tonys. I got there at 3:00pm and was the 8th person in line. Even though they only have a certain amount, there were people who still stood in the line past the last person that would get tickets. I was past there last week on a hot day and the line was not that long. I suspect people got there, realized they were probably not getting in and left because of the heat.
Is it worth it? yes, it is. I was offended by the end of one song but the show, overall, is very good. is it worth the premium prices? In my opinion, no. But for me, no show is worth paying premium prices. The view from standing room is great and even after standing for 3 hours to get tickets I guess the excitement made it easier to stand for the show. It is a bit cramped back there during walk-in and intermission so I wouldn't take bags in with you.
Just give the world Love. - S. Wonder