Advantages: + Beautiful bokeh + Very high light intensity + High sharpness Disadvantages: - Slight color fringes at 1.4 aperture. (Optimal use 1.6 or 1.8) Application: - Portraits: I use the lens as a portrait lens on a 500D. The crop factor of 1.6 makes it the ideal 80mm portrait lens with a very nice cropping when the aperture is wide open. Due to the high light intensity, I can also take pictures in adverse light without any problems. The lens is also very well suited for outdoor shots of whole people, provided you are at a certain distance. I've had the lens for a month and haven't even looked at any of my zoom lenses since I'm so impressed with the image quality and speed. Alternatives: - Cheaper: Canon 1.8 50 mm (-worse image quality + much cheaper) - More expensive: Canon 1.2 50 mm (+ better image quality + slightly higher light intensity - completely different price range.) - Third-party manufacturer: Sigma 1.4 50 mm (+ slightly better image quality - should often have focus problems) - third-party manufacturer: Planar T* Zeiss 1.4 50 mm (-no autofocus +-image quality comparable +Zeiss)