Don't hesitate if your upgrading from the older, cheaper EF 50mm f/1.8 STM Lens. You won't regret it.
This is a great lens for the enthusiast. I upgraded from the EF 50mm f/1.8 STM Lens and it captures the image so much better. It's a bit heavier than then the f/1.8 but the f/1.4 will have more glass, better build materials (more metal and less plastic) and the focus ring is a proper manual one and not electronically coupled with the camera.