I have worked in both Google and Microsoft and even though I see how people can be efficient in Critique, I must say I prefer CodeFlow.

In CodeFlow any comment is a floating object with a line connecting it to whatever selection it was created for and you can move it around as you like. You also can easily filter out visible comments by state, author, participation in them.. Features around comparing iterations, marking already reviewed files and similar are the same as far as I remember.

Another reason for my opinion might also be that CodeFlow is probably better optimized for large screens, but this might be caused by the weird Google standard of 80 column limit for source code which I will just never understand in the 21st century where everyone has 24" and up full HD to 4k screens.

I am comparing state of both from 2015 where I worked with both in the same year.