I've run more than a dozen rolls of film through my camera for this lense. It's been fun a challenging to seek lowlight situations and let the lense work its magic.
Because I really wanted the 85mm in the future, I bought this lense to test some high school gyms because I can't use flash during basketball games. The first test I was able to achieve my best photos at f2.8 but at wide open there were no usable photos that didn't suffer from motion/blur. I was using ISO1600 film and achieving some super fast shutter speeds. Too inexperienced to understand why that is but it was super at 2.8 or a stop below with more moderate/slower shutter speeds. It was overkill at f1.4 with poor results.
For sports, the obvious limitation was its focal length. Hope to get to use it at some boxing matches in the near future.
Next was my photography class project. I was shooting an abandoned railroad bridge and it worked perfectly at all times of the day, at all apetures. Even mounted it on a tripod and did some night shots and to achieve the desired light trails from cars and it worked like a charm.
Final test and the reason anyone would own a f/1.4 was available light shots I took indoors on a cruise to the bahamas. It was my only lense. I can't say enough about the quality of photos my N80 and 50mm produced in and around Nassau and on the ship. Stunningly sharp! The biggest test was dinner at night in the ships dark restaraunt. ISO100 with Fuji was very limited indoors. ISO800 Kodak was a breeze. In the very darkest situations I achieved shitter speeds of 1/30 and 1/60.
My opinion that in normal indoor lighting this lense will handle any situation, easily! The one drawback in its intended use is that it almost too crisp in its focus. For example my wife and some inlaws were sitting in a piano bar and they were only slightly seated further back than the other. My wife was in focus but the others were not. It could be a combination of things from shooting in the lowest light, wide open apeture, slowest shutter speeds, and my inexperience. I also experienced this with my cat on some other rolls I shot.
But I guess for most normal people this is supposed to be a portrait lense, but I found it very versitile thus far from street, landscape, indoor shooting. The light gathering capabilites of this lense is amazing.
Will I spend $600 more to get an extra stop on the 85mm? Probably not...
Is this lense worth an extra $179 as apposes to the f/1.8? Buying this lense was a smart purchase for my situation. I would reccommend it to anyone that can't or doesn't want to use a flash. I just love that freedom.