Being intellectually honest, I'd have to say that they aren't really comparable. The low acceptance rate is true, but the sheer amount of completely unacceptable applications that are filled out after seeing one of these "make 75k in 3 months" ads contributes heavily to the percentage.
I attended this school and while most of my classmates were highly-intelligent people of diverse backgrounds, I can absolutely say it is much easier to get into Flatiron school than any of the programs listed above.
I've heard that many people who don't know any coding at all often apply to bootcamps and simply just flunk the first coding assessment they get. They probably help account for much of the low admissions rate at any half decent bootcamp (that have coding assessments).
I attended this school and while most of my classmates were highly-intelligent people of diverse backgrounds, I can absolutely say it is much easier to get into Flatiron school than any of the programs listed above.