We used to live within walking distance of the light rail and loved using it, it was so convenient! We use it a lot less now, but still use it when we can. My main complaint is timing, it is not the most frequent of trains, but that is mostly due to the market. It is incredibly cheap compared to most cities' public transportation and you can get an all day pass or a one ride ticket. It is a great way to get around the downtown, Tempe, and Mesa area. It is not the most extensive system by any means, but it will get you to a lot of the major hotspots, including the airport. I give it 4 because of the timing and occasionally the cleanliness. My 2 year old absolutely loves it and it can be a fun and convenient way to get around. Even on the busiest of days it is a great way to get around, we have never had an issue.