I had a brief stop in Vegas and needed to get downtown with a minimum of time and expense. Taking the WAX was a terrific way to do so. The stop is right outside McCarren and the wait for the bus will likely take less time than waiting in the horrendously long taxi line. Plus, you get karma points for taking public transit instead of adding to local vehicle pollution.
The WAX route hits all of the major points in the area and does so in a quick and efficient manner--for a bus, anyway. The only real downside is the number of people smoking directly near the bus stop.