I've been to Las Vegas annually (for roughly 1 week at a time) and this was the first time I tried the Mandalay Bay - Luxor - Excalibur tram. I've never had any reason to journey south of Tropicana/MGM before and the one time that I did, I was with some friends and we had a car.
I found the tram to be great. I used it during my April 2016 vacation when I decided to go to Mandalay Bay to take some pictures as well as visit the hotel/casino and I didn't feel like walking in the Las Vegas heat. My only complaint would be that it is somewhat on the small side and there are not a lot of seats (however, it is only 2 stops or 1 stop to your destination).
Best of all it is free and air conditioned.
For this trip, I rate them 4.5 stars (which rounds up to 5).