No its not that bad. The bad thing it doesn't go away that easy when stopping down, most because it isn't simple softness but a mix of distortion, curved focal plane, vignetting and CA's. Usually lenses are soft wide open and get ok after few stops(F4..F7 reaches sweet spot). At 10Mpix, you don't get completely away from CA's at moderate contrast even at F9.
Using F1.4 lens in such a way is just an irrational expense. But still im after the punchy contrast and colour sharpness you get with a quality fixed focal lens. Sigma has it, but with additional price of F1.4.
Here is a sample @F9. Its ok even when viewing on 19", CA's are barely noticeable, (if you search for them), visible in prints (but if im about to print anything its good enough reason to correct anything i can - distortions, CA's, exposure, etc), sharpness is acceptable.
P.S. And the 28 was 105$ with shipping.
Last edited by ytterbium; 05-11-2009 at 12:55 PM.