Not sure why I've never rated McCarran. My parents and I used to go to Vegas ALL the time when I was in middle and high school (so like 1998-2004 or thereabouts). I had a 2-hour layover here today and wasn't too broken up about getting to play some slot machines for a bit :P.
The Southwest terminal has some great eating choices too - I had Nathan's, and there's a pizza place, Wendy's, Popeye's, Jersey Mike's, and more. Yum. The airport is big but is easy to navigate. There are shuttles to get from the "outside world" to your gate, as I recall.
I had an easy layover here today and would recommend it for that or for direct flights.