For a city as extravagant as Las Vegas, McCarran isn't exactly the most exciting airport. It gets the job done. You fly in, you grab your Uber or Lyft, you come back, you go home. There are some slots, some eats, but overall a rather drab look to the airport.
What's unique about this airport is the slot machines. But if you're coming back from Vegas, I'm sure you're already all played out.
One thing I will note is that there are some more "modern" accommodations here (and it's kind of sad that this is considered modern rather than expected) like USB ports to charge your devices, though I guess those will soon be out of date thanks to Apple.
My biggest gripe is the layout of the airport. You never really think about the layout of the airport too much, but as a "frequent flyer" it does impact me. The Centurion Lounge and the Club are at Concourse D, and Southwest doesn't fly into Concourse D. It's accessible from Concourse C, but there's a shuttle that doesn't come all too frequently. To sum it up - it's a pain to get from lounge to gate. Not SFO painful, but up there.
Would also note that CLEAR is virtually useless here, at least in my experiences. TSA Pre gets me through most of what I need to, but maybe I'm not traveling at peak hours. Who knows.
TIP: You kind of have to go through here to get to Las Vegas.