Excerpt: I know it's expensive but, buy it. Try to find a deal, sell one of your kids or donate a kidney, get it. I have been using the 17mm 1.8 as my primary for the last two years. That is one nice lens and I have no complaints about it but, I found myself wanting more of the scene as opposed to less.
Pros: Consistent Output, Durable, Easily Interchangeable, Fast / accurate auto-focus, Lightweight, Nice Bokeh, Rugged, Strong Construction
Cons: Expensive, No lens hood, No Protective Bag, Why Not 18, Why Not 18mm
Excerpt: This is my second lens for my Olympus OM-D E-M1 after the 75-300 mm Zoom. With a 35mm equivalent of 24 meters this works as a medium wide prime lens. I have gotten fantastic landscape shots with this lens with good color. This lens lets in plenty of light and works great for outdoor photography.