I do find the extra bit of brightness a help in low light, although I agree that it is minor. I don't see much of a quality difference, but then that in itself is quite something as it is harder to make faster lenses. At the time, there was a huge price difference, but not any more on the used market and I have been slowly replacing my OM lenses with the faster versions. I recently got the f2 35mm which is a lovely lens.