Took a Waymo for the first time a couple weeks ago, 20 minute drive. Did a pretty good job. There were a couple times where I wasn't sure what it was doing... minor things like signaling to turn left but then decided to go straight instead last second, getting a little too close to a curb, etc.
However, it never did anything illegal as far as I could tell. The biggest issue is other human drivers. Since they do illegal things all the time, Waymo has to be extra cautious, which causes longer waits at intersections. Saw a human driver blow past a stop sign when it noticed it was Waymo's turn to go. π