I rushed yesterday, aka August 23rd, a Wednesday. My two friends and I arrived at 11:30. It was raining, which may have contributed to the lack of people. At 12:40 a couple showed up, their friend would later come. The next person showed up at about 3, and one of their friends also showed up later. After that, I began to lose track of the numbers of people showing up. At I would say 6 or 7, there were about 30 people in line. By the time the box office opened there were over 50. I'm not sure how many people got tickets.
As for where our seats were located, the 8 first people on line bought tickets to the evening show and got them. My friends and I, the first 3 people, got stage seats. With two of us having an almost unobstructed view of the show and having the actors frequently interact with us. In fact, I was even one of the people handed a love letter by an ensemble member. The other 3 people behind us got a box to themselves. It seemed like a good view, though they didn't get interacted with.
However, one of my friends, the 3rd person in line, couldn't see a good portion of the show. They were in a stage seat all the way to the left if you face the stage, and were behind a good amount of people, some of whom had elevated seats. According to them, they couldn't see the left half of the stage or the Mezz, where the performers would sometimes go.
As for the stage door, a lot of ensemble members came out and about 4 people from the main cast. Most notably, Dave Malloy aka the current Pierre came out and took pictures with everyone who asked. Neither Lucas Steele nor Denee Benton came out. There were about 50 or so people at the stage door, it was what I refer to as a "layered" stage door, as there was a front row touching the barricade, and a back row of people also trying to get signatures. This may have been because some people had seen another show before, and we were near the Hamilton stage door though.
Overall, if you're interested in seeing The Great Comet I think it's worth the wait. I would highly suggest you try to sleep if you're there for more than a couple of hours. Bring a blanket and a pillow, you will be exhausted. The pizza cafe on 8th ave and 45th street has an open bathroom in the back to the right, it's a life saver if you have to go. Just try not to get the seat my friend got, especially if it's your first time seeing the show. (It was Table TC for those wondering).
Hopefully this was helpful, and if you have any questions feel free to contact me 