This is a fun show. It's short (less than 10 minutes) but it's still action packed. Also the crowds here don't get as packed as for the Bellagio fountains so it has that going for it.
Just be aware that if you stand behind the volcano (i.e. the lobby of the Mirage) it will get extremely hot and smell heavily of gas. After the show it felt like I was sunburned. It's still fun though, and worth exposure to the heat.