Students cutting hair. Not as scary as it seems. I've been several times and consistently get a good a cut.
For buddha's sake though, spend the extra few bucks and get a phase two student for a mere $17! I did and my cut only took a little over an hour and looked awesome! They tend to be quicker and more confident than phase ones. There are also less students in phase two, so their instructor is more readily available.
If you've never been, the student cutting your hair needs to be checked off by an instructor. This ensures any mistakes are corrected, but also means the wait is longer if the instructor is busy with many students at once. I've gotten cuts from phase one students in the past that have taken nearly three hours between their general inexperience and having to wait for an instructor.
*You can pay with card, but can only tip in cash.