The pictures below illustrate the angles of view on 35mm full frame and APS-C (1.6x crop) camera bodies. Our observations indicate that the focal length is noticeably shorter than the specified 50mm (probably closer to 47mm):
Class-leading image quality; Relatively low vignetting even at wide apertures on full frame; Reasonably fast and positive autofocus; with full-time manual override; Very good build quality
Large and heavy for a 50mm F1.4; Expensive