With as much travel as I do, I know good airport security operations from bad ones. And the Terminal 1 "D" checkpoint at LAS is a cluster. One check-in person for both regular and Precheck. Long lines not moving. And when they opened another line for PreCheck, there was no clarity about how to navigate the rope lines to get from one queue to the other. So it was a mess.
That said, once my ID was checked and I somehow wasn't selected for additional "random" screening despite my attitude, it was speedy and I was able to get over to the regular line just as my Mom was coming through the regular screening.
Ugh. If I could go elsewhere, I would.