I'm looking for a prime in the 20-30mm range for landscape/cityscape work for a crop sensor camera. I would mostly use it in low light and night photography shooting cityscapes on a tripod, so a lens with low flare is necessary, while fast apertures are not - I usually shoot between f/4 and f/5.6.
I've read some reviews of Canon's own primes, and the slow lenses get very bad reviews, with complaints on vignetting and flare. But I'm not willing to shell a thousand euros more just to get a few stops of speed I never use.
Any recommendations, Canon or otherwise?