Rating 9.7
I bought a $10 card and rode all over the city over two days. Every hotel/restaurant has a map and the lines are color coded and easy to figure how to get from one point to the next.
Best thing is the stations are modern with display board that give an ETA on the next train (hello "L" in Chicago), downside is they are hot during the day and crowded at peak travel times.
Riders are families to business people in suits (me) to everything in between.
I do need to warn that each rider needs their own individual card to travel, and that you put the card in at entry and exit (there is some kind of metered system where money is deducted).
But it easy, timely and fun to ride.