This review is for T1 (just for clarification)
Overall my experience at McCarran has been decent, I've never been late to a flight and security lines have never been an issue. For departures, the D gates are definitely the nicest, when I flew Southwest I had another gate area and it was very dated with low ceilings and not a lot of space.
Baggage claim is reasonably speedy and it's not a big walk back to long-term parking which is a plus. I really wish the baggage area would get an upgrade as this is where many of our visitors get their first look at Vegas. In some ways this area is stuck in a time warp around the mid-90s.
Parking fills up on holidays so more often than not you'll have to loop around and drive to the economy lot and wait for a shuttle. I don't dread this airport, but it is not as well laid out as my home town Detroit (DTW)