Conclusion: Whether you opt for the 1.2, 1.4, or 1.8, every photographer should have a 50mm in their bag. I chose the f/1.4 strictly for the combination of price and performance. This lens rarely leaves my camera body, and is really diverse enough for almost any situation. At f/1.4 I usually switch over to manual focus to get the right shot, but leave it on automatic at f/2 and above. The AF is not quite as fast as some other primes, however it is not an "L" either.
Summary: I researched this lens extensively. I was aware of the auto focus failure but saw so many good reviews on amazon that I jumped. My copy was defective. It is amazing that canon knows about these problems but doesn't change the design or improve on their quality control. The issue with my lens is that it does not focus through the finder. Up close it rear focuses. Past 10 feet it front focuses. Very frustrating. I never had this issue with a canon lens.
Conclusion: Pros: When it focuses where I want, the image is stunning. Good low light captures of still objects. Cons: It takes skill to use I use a T3 Summary: Build quality is good, the Lens quality is great, it certainly does what it says, just realize what you are getting. Autofocus takes a while, but there's a reson for it. Before I review the product, I always like to know the reviewer's perspective. I consider myself a seasoned novice photographers.
Conclusion: I needed a lightweight, inconspicuous all-purpose lens to use with my Canon 6D for family, landscape, and reasonable close-ups of flowers & wildlife while visiting Colombia. This 50mm is my least expensive yet sharpest EF lens between f4 -f8. Very good focus, nice colors, low distortion. did fine for night time and street photography - a bargain.
Pros: Fast auto-focus, Super-sharp images, low distortion
Summary: Excellent image quality, and excellent for low light. A little soft wide open (which can be a nice effect in itself, if desired), and sharpness is very good when stopped down to f/2 - 2.8. As far as value for the money goes, it doesn't get any better.