Camera: Sony NEX-5
Lens: E-mount 18-55 vs. A-mount 28mm
The first two photos use the Minolta 28mm. This is probably the least-regarded of the Minolta primes. The third photo uses the 18-55 kit lens.
Below are three 100% crops from the above three photos. This really isn't the best comparison, as I didn't use a tripod (hand-held), and perhaps had a bit of motion blur, which would be more noticeable at this magnification, or more likely the focus is just a bit different. Still, on average, I think there are more details in the Minolta lens photos.
Conclusion: I think the Minolta 28mm is sharper and resolves more detail, but the 18-55 is not bad. You really have to look magnified at the pixel-level to see any difference. The bokeh of the 28mm is kind of strange; the 18-55 is better overall, although without being able to go wider, it is not as smooth as one would like. In many cases the 28mm is smoother, if you can look past the oblong bokeh highlights.