We report preliminary observations of changes in responses to student surveys over a five year period in an advanced laboratory course for third-year physics majors at the Massachusetts Institute of Technology. This period spanned the introduction of curriculum reforms which included the use flipped classroom techniques - facilitated by the OpenEdX platform -- for those aspects of the course material which had previously been taught by direct instruction, such as data analysis techniques and basic laboratory instrumentation. Not all variables of the classroom environment were controlled during the study period, so flipped classroom techniques cannot be identified with full confidence as the cause of the measured changes. Survey data was collected using the E-CLASS and institutionally administered subject evaluations. Improvements were observed in some metrics of interest to the course's strategic goals -- notably in students' self-reported hours per week spent on coursework and in the overall rating of the course -- while negative or null results were observed in other metrics of interest.