Before Sarvam Thaala Mayam, my impression of GV Prakash is that he is a really good music director who has composed some of the best hits in the Tamil movie industry. I had never rated him as a good actor perhaps due to the types of roles that he has done in the past.
My personal favourite is his composition for the 2010 Tamil movie, Aayirathil Oruvan titled “Maalai Neram” sung by Andrea Jeremiah. He also did a great job in music scoring for other blockbusters like Madrasapattinam, Deiva Thirumagal and Raja Rani. Image source: Wikipedia.