Summary: Currently my favourite prime to use. On my full frame this is such a versatile lens and I love the look it gives. It's not overly wide that it starts to distort like ultra wides, but it's wide enough to cover a good landscape shot, or to do fantastic environmental portait shots. I would defer to genotypewriter for his expertise on this lens. He has had a lot of experience with this lens. I really enjoy using this lens for late night astro photography based landscapes.
Pros: Very sharp lens, gorgeous build, amazing low light performance.
Cons: Nothing major, but the lens hood is a touch too loose.
Summary: I continue to find new uses for this lens. It lends a beautiful, artsy feel to your photography. Portraits, candid shots, and I even use it for interesting still life or detail-type shots. It's a very useful lens but also a fun lens to use!