Superstar Aamir Khan is overwhelmed with actor Ranbir Kapoor’s performance in ‘Ae Dil Hai Mushkil’, and called him a great artist.Aamir took to Twitter to laud filmmaker Karan Johar’s directorial venture.‘Ae Dil Hai Mushkil’, also starring Aishwarya Rai Bachchan, Anushka Sharma and Fawad Khan, clashed with actor-filmmaker Ajay Devgn’s ‘Shivaay’ at the box office.‘Just saw ‘Ae Dil…’. What a film! I just loved it! Karan has hit the ball out of the stadium. Ranbir, Aishwarya and Anushka have just killed it. Ranbir is the best actor! Period! A must see!’ Aamir posted.Produced by Fox Star Studios and Dharma Productions, the film released on Friday.