I bought this 28mm prime lens mail order for a Canon 20D because I wasn't happy with the sharpness of the Canon 24-85mm zoom which I have been using for indoors situations and landscapes.
The 28mm f2.8 is cheap to buy but is certainly no little gem.
I've used it for just under a week and mostly for landscapes.
Any light from the sky seems to cause the edges of building to take on a red edged inner glow whilst small details are lost by the soft focussing.
During the same shooting day I used the same Canon 24-85mm zoom that I'd been dumb enough to be unhappy with before, and found the images to be noticeably clearer and crisper at the same focal length.
Perhaps it's down to QC variability but frankly, I can't recommend this lens, no matter how inexpensive it is. I've learnt my lesson and I won't be 'buying before trying', ever again!