We have one lady at my gym who is this-certified and that-certified and is always going on retreats, etc...she is awful. She is far too concerned about how a pose looks, even if the student isn't physically able to make it perfect, and she is always coming around and pushing you into positions you can't do without help. It doesn't make for a relaxing class. Plus she is a creepy-toucher.

My favorite teacher is a sub who is really only qualified to teach pilates.

Certification, while it implies knowledge, does not necessarily mean they can impart that knowledge effectively to others! Good luck and I hope it's everything you expect