Studying pervasive systems in the wild has recently gained significant interest. However, few methods exist that focus on the subjective of user experience of such systems rather than objective metrics, like performance and task success. Especially multimodal interaction in this context poses challenges to understanding how different input and output methods affect the users' experience. We present a new method for evaluating the experiential user experience of interactive systems. It combines two existing approaches from different fields: a questionnairebased evaluation method called SUXES, intended for evaluating user expectations and experiences, and a theoretical experience framework, Experience Pyramid, originally developed for analyzing and improving experiential tourism products. The new method was used in two field studies of multimodal public display applications. Our findings show that the method is a practical approach for user experience evaluation in the wild, especially in the case of pervasive applications that aim to provide novel experiences rather than facilitate task-oriented information access.