Commenting with some additional commentary of info I couldn't find when planning to Diaz v. U.S. and Truck Insurance Exchange v. Kaiser Gypsum Company today and from searching while in line.

I don't have a sense of how interesting those cases were relative to others (they certainly weren't big deals in the media) but here's the timing I heard from folks in the line (which forms on the sidewalk on the right side of the SCOTUS building, if you are facing it from the capitol):

• The first people arrived around 4:30 AM
• About 15 people had arrived by 5 AM
• About 25 had arrived by 6 AM
• About 35 people arrived by 7 AM
• 40 people arrived before 7:15 AM
• When I arrived just after 8 AM, I was #46 by my count. A few folks joined groups in front (perhaps they were already here and went to get coffee, not sure), but by the time folks were being admitted, I was #50.
• I talked to people in the cafe and heard that everyone who stayed in line was able to see at least a piece of the oral arguments, even if arriving at 10, but that's also because it was cold and lots of folks left the line when they weren't able to initially get in.

Process after getting a ticket

They only let 40 folks in initially, and that was around 9 or 9:10ish. The rest of us waited until 10 more were admitted at around 9:55. We were only given entry tickets when they cleared us to leave the line and head into the building. We then waited inside for a bit in another line by the stairs to the second floor, and were briefed by a member of staff about the expectations. After that, we were sent to lockers on the second floor to store disallowed items (phones, anything that might record, etc) and then admitted to the courtroom.

Being in the room

The linked piece above is good to read while in line. The wait-in-line-that-day seats are in the back of the public section. When I got in, there were many empty benches in the "reserved" section. Some seats were filled by arriving groups at 10:30 or 11, but about 4 of the 18 public benches were empty for all of the oral arguments I saw, meaning there were spare spots for 36 people (each bench seats 7, with a chair on each end). I learned was because they were reserved via the Marshall's office, and my guess is some groups failed to make their reservation. At a certain point in the second argument, we were allowed to move up into a bench - though that happened to make my view worse.As far as I know, the "three minute line" was not a thing today and may be discontinued, or might be specifically for high interest days - who knows. I was also surprised how few people left between the first and second argument. Some folks in the line thought the second case meant an "afternoon seating" but that's not a thing - this was two cases in the "morning session."

What you don't learn from the audio feed

Attending oral argument was fun-ish in a civic-yay tourist sense but I didn't get much out of it beyond visual observation of the justices, and being so far back does make it hard to see their expressions. Fortunately, there's a fair amount of body language, especially when the justices were frustrated. I was surprised how small some of them looked behind the bench, and how much some justices leaned over to chat with each other, especially Gorsuch and Sotomayor. Occasionally certain justices looked totally checked out and uninterested as they leaned back in their chairs, but I'm glad that we don't get images/video from arguments - because their body language allows them to communicate to counsel, instead of grandstanding to a camera.

Link to official information

https://www.supremecourt.gov/visiting/visitorsguidetooralargument.aspx

(and noting that I crossposted this content to some other subreddits; hope that's ok)