As a born and raised resident of Las Vegas, I am very familar with this airport. I have seen it go through endless changes, and I am pleased with the progress. It has become very efficient, and appealing to the masses.
I have been to many airports, and this airport like others can become crowded at peak hours. Most of the time, the crowd moves quickly and it is tolerable. Picking up passengers is alot easier than dropping off. The trouble lies with taxi/limo/everyday drivers will just stop their car in the middle lane causing a bottle neck. One change I appreciate is level 2M in terminal one garage is reserved for ride sharing (uber/lyft) pickup. The airport itself is usually under construction regularly to increase efficiency. However, the airport remains pretty clean. Also, I love that there are so many outlets everywhere. Food can be scarce at times. They do close around 9pm so if you have a late flight 24/7 food does not apply within the airport. Keep your eye on the prize...getting home.