3.5 stars. Good option if you have time. I had a friendly driver. This was the cheapest airport shuttle (only $8 one-way to hotels on The Strip).
You can purchase your tix online, or just do it in person at the airport booth (credit cards accepted). It will take you forever, however, because they stop at every hotel, as requested, on The Strip. It took about 40 minutes between LAS and Bellagio, whereas a drive would only take about 15 min.
Because there's no public transportation that takes you directly to the airport (frustrating, considering the hotels are literally across the street), your options are limited to either the airport shuttles, taxis (there could be a lot of traffic), or rental car. You can't walk across that crazy freeway either.