I've been at this studio taking group reformer classes for almost 2 weeks now and so far, so good! I've taken classes from 6 different instructors and all of them seem knowledgeable about proper form and technique, and are patient and willing to lend a hand to correct you or help you. The only area for improvement would be not letting class members "reserve" machines during a group class. Unless someone owns or purchased that machine, anyone has a right to use it if he/she arrives first. We all paid in equally to be there.
Also, THANK YOU for offering the first trial class for free so that people can give it a no-risk try to see if there is a fit. Other competitor studios like Core Pilates Studio will charge for the trial class, and so I essentially paid for an awful experience. By maintaining your policy, you will get more conversions to membership because you are confident of the positive experience your customers will have.