For me, prime lenses are about speed, quality, simplicity and compactness, with bright viewfinder images which snap in and out of focus.

I find there is also a unique pleasure in using a fast primes which has nothing to do with quality per se, but is more to do with a feeling of getting closer to the roots of photography. For me, a prime lens is good, but using a prime lens and waist level finder is sublime, and even transcends the joy of taking a roll of freshly developed (and even correctly exposed) Velvia out of the processing tank!

On a more practical level, for days out I will often take only my OM4Ti with Zuiko 35 mm f2.0, which I find a lovely lens to use. I did once buy a 28 to 70 mm zoom for it, but I never felt happy with the zoom, and sold it after a few months.

I think there is also something rather magical about the look of big glass elements in some of these lenses, and the feeling of a small but high quality package.

If I could buy a fast prime for my E1 I would, but it would need to be the equivalent of a 50 mm 'standard' lens, preferably f1.8 or faster; or better still, a 35 mm f2.0 equivalent.