We checked in on 7/20 - probably around 11 or 11:15 AM. It took at least 45 minutes. There were 5 people in front of us and it took forever. Two or three agents were working the desk.
We saw a sign for the line for mobile check in, but we couldn't figure out how to even start that process to shift lines.
When they sent us the text for our room (got the text at 1:30), they said our keys were correct and we could go right to the room. We tried that, walked to the room, and the keys didn't work. I walked back down to the desk and there was no one in line. This was some time in mid-afternoon.
It's all down to timing and luck.