Yes McCarran has made overall improvements, but Southwest still has some of the slowest security lines, geez! Hundreds of people in line and there are (2) TSA agents with (3) conveyor belts/metal detectors.
I requested a pat down in lieu of the body scan and the poor TSA agent had to yell for a female assistant four or five times over a 20 minute period before anyone showed up.
The Southwest gates are probably the furthest gates from the security check, but there are plenty of snack stops and bathrooms spread out along the way. The bathrooms are very clean and have plenty of stalls.
5 stars on the remodel
3 starts for efficiency and speed