This paper assesses current trends in diffusion performance practice. It aims to identify the most important stages of development in diffusion and its related fields, and how historical events have continued to influence modern diffusion practice. The main focus is on advancements in spatialisation techniques and the way they helped catalyze new movements in diffusion. A split in two schools of thought within diffusion is recognized and each of these is discussed. The paper also looks at the way both stems of diffusion have more recently, embraced the design of custom interfaces focusing on the ways they aim to increase spatial expressivity in performance. Three main areas of diffusion interface design are discussed in depth and examples from each category are given.