This is the real deal. I have been to many Ashtanga shalas in the world, but nowhere have I found this blend of relentless intensity and focus on the practice, with a warm, welcoming community and a pressure- and ego-free atmosphere. Andrea and her team teach in the tradition of Nancy Gilgoff and Manju Jois, emphasizing flow and breath over geometric perfection. Showing off is actively discouraged. No two bodies nor two minds are alike, and here the teachers want to help you with yours, instead of insisting that everybody must accomplish certain benchmark feats before progressing.
Whether you can't reach your toes or you float through third series on one hand doesn't make a difference here, what counts is devotion to the practice and focus.
One thing that really sets this place apart from pretty much any other yoga studio I know is the amount of communication among teachers: If Andrea wants you to work on a specific element of your practice, if Cathrin showed you a particular modification for an Asana you struggle with, if you told Astrid about a new injury, chances are that all other teachers will know about it and incorporate it in their teaching.
This place has been around for nearly 15 years now, and it is easy to see why. Yes, it is a little more expensive than other Yoga studios, but if you are serious about building a healthy, holistic, long-term Ashtanga practice, Andrea is the teacher you are looking for.