Looking at the 2016 California DMV disengagement reports, Cruise is at 181 disengages in 9,776 miles of testing in California for 2016. This can be compared crudely to Waymo's 124 disengages in 635,868 miles for 2016.
Waymo's operation is 2 orders of magnitude more advanced than Cruise, but in terms of video demos, we haven't seen much of the environments Waymo's cars are capable of navigating. Waymo has only revealed their cars driving on suburban roads, it seems only Cruise is tackling hectic downtown driving head-on.
GM, with their Lyft partnership and Orion assembly plant is, I think, in a great position to deploy early fast with 1st gen robotaxis.