None is really better than another. Most of it is just BS public relations. USADA doesn't do any tests! They are the bureaucracy part of an administration process for testing. Phlebotomist jab the needles in the arms to collect blood and piss watchers collect the samples from the athlete and then samples get sent to labs where the testing is done. There is a list of banded substances but it depends on what gets checked on the forms as far what substances actually get test for. I'm guessing the checked list is set by the athletic organization, although the requirement is most likely set by the governing body. You could probably find the specifics and standards for testing on wada's website.

Every procedure is open to corruption when bigger money is involved and no matter how prestigious or un prestigious an organization is.