The Sigma 35mm f/1.4 Art continues to be my go-to lens for indoor events. Partly because of the focal length, partly because it's a really good performer in the IQ department. That said, the Sigma 50mm f/1.4 Art is a lens I would be happy sticking on my camera and not taking off for 3 months. It's an unbelievably good lens. As long as a 50mm focal length suits the situation, it'll be on my camera.