Arrived in Vegas and needed a ride to my hotel. Found the first booth that sold airport shuttle tickets, paid my $6, got my token, and off to the shuttle I went. Was in my hotel 15 minutes after that, after 2 quick stops to drop off other passengers.
Best to use this service when arriving in LV, rather than leaving, because then you don't have to wait for the shuttle to pick you up at the hotel. The wait is typically longer on the way back to the airport. Just take a cab which would be faster, although double the price (still less than $20).