I've been to a lot of airports. McCarran is not one of my favorites. It has a few good items: 1) you can play slots in the airport - great when you have a layover, but maybe not so great if you've just lost all your money in Vegas and 2) you can buy alcohol from stands and drink anywhere in the airport - once again great for layovers, maybe not so great aver a Vegas vacation.
Now my issues. The tram is ok in the one terminal, but to get to the other gates it's a bit of a hike. We were there from about 4-8 pm on a weekday and some of the places in the airport were closed (including the Chili's for dinner). Their food options are somewhat lacking and there is definitely the hang-over vibe going on.
The landing is pretty cool if you're on the right side of the plane since you get to see the Strip and you have a few peek-a-boo view from inside the terminals. It's been a while since I've been through security here, so I can't comment on that, but overall it's an ok airport.