As a frequent Business traveler I must say McCarran is a good airport. The set up is really good for not just inbound but outbound flights. The check in process to the gates is pretty smooth and even with heavy traffic things move quickly.
The baggage claim process is a letdown. It is slower than most airports. May be aging equipment or a airline staffing issue but 30 minutes plus from arrival is the norm. The drop off and pick up process is really good. The fact you can pay for parking in advance makes things even better.
I picked up a rental once and that was not as good as it should be. They need more buses to shuttle to the offsite rental faculty. Overall a good airport.