1) The amount of rigor and work required for the Stanford classes was significantly less than the UW classes. I spent as much as 10 hours per week on the UW homework in addition to the 3-4 hours of video lectures. That's against about an hour for the Stanford homework and another 60-90 minutes for the lectures. I agree with the OP's description of the ML homework as starting out at a decent level of difficulty and quickly becoming trivially easy.
2) I found the format of the Stanford lectures considerably easier to follow. By making a canned recording, there's a huge amount of dead time which can simply be edited out of the lecture. That plus the ability to watch at 1.5x speed meant that I was rarely tempted to do something else at the same time as watching the lecture -- something which frequently caused me trouble with the UW classes.
3) The UW classes were something like $3500/course. If my employer hadn't been willing to reimburse me, I wouldn't have taken them.
All-in-all, I think the Stanford classes are great experiments in which I'm happy to participate. I'm planning to take five of them in Jan-Mar.