I've been there two times and the results are mixed. First visit was with Elham, and she did a pretty good job. I decided to return and was assigned Lucy. Lucy unfortunately did not follow instructions well ... I asked for 1/2" off the top and instead she buzzed my hair all the way down TO 1/2". I'm not sure how I could be clearer as the little piece of paper they print off also has the same instructions. Sometimes it sucks to wear glasses because you can't see what the stylist is doing...
In anycase just be careful and repeat your instructions multiple times and hope for the best ...