I quit because I felt like I was being held back. They rushed me through all the certifications within the first year and then left me hanging out for the next 3. I had a lot of great opportunities outside of MAC, and my trainers didn't like that very much. Also, the schedule thing is not a joke, whether you work 10 hours a week or 30, that counter owns you. Any shifts, any days, and they reserve the right to tell you, "oh, well it's not confirmed yet, so don't plan anything", up to and including that week. So forget trying to work around your MAC schedule to be a real makeup artist. They don't want you to be one, and they're not going to help you.