I started doing Chloe Ting's workouts, and I saw major results. Now, I don't really do them anymore, I do Pamela Reif's because it's more challenging, and I get better and quicker results from it.
But if you want to do Pamela Reif's workouts, keep in mind that she doesn't have breaks(that took me a while to get used too) so I just did her beginner ab workout and it worked just as well as her more intense ones(and it has breaks!).