Don't know what it is about Tasha but I find something rather 'manufactured' about her dancing, possibly because she has worked as a professional dancer. To me her undeniably perfect appearance and performance lack personality and passion, and I dislike the too frequent references to bullying throughout the series.
Chris makes very little reference to his lack of vision other than as a joke. I noticed at the end of the opening dance one of the professionals was instantly at his side to guide him off the dance floor, and thought how terrifying it must be to be in an unfamiliar environment surrounded by noise, flashing lights and dozens of people, aware that millions are watching you.