I have Olympus's 25mm f1.8 prime too, which is more expensive, but I think this 45mm version is sharper. Its also just as neatly built, compact and performs just as well in terms of fast and accurate focusing.The 45mm length (90mm in 35mm terms of course) is useful for more than you'd think. Perfect for portraits, it's also great for giving a different perspective on landscapes and cityscapes. I've used it at classic car shows and although it's more tricky to get shots in confined spaces, it's worth the effort to get that slight telephoto look with the extra isolation (i.e. shallower depth of field) you get because the lens is a bit longer.Sharpness is the outstanding feature of this lens though. You notice it from the first shot you take. It makes you feel like a pro. As does the lovely rendering of out of focus backgrounds and a special 'quality' about the photos it takes that's hard to define. Contrast and colour are so good that you'll barely need to adjust your photos in Photoshop or the like. It's hard to take a duff shot with this lens.The only slight downside is that you don't get a lens hood or carrying pouch with the lens but you can pick them up very cheaply if you need them.The bottom line is that this is a near perfect and therefore essential lens for a bargain price. And it's my favourite Olympus lens so far (I also have the 17 f1.8 and the 25 f1.8).