Once the 14-54 is manually focused right, it appears to be comparable to the 14-54 Mk II in S-AF.
In terms of sharpness, I rank from 1st to 4th :
1. 14-54 Mk II
1. 14-54 (tied - only when manually focused)
3. 12-60
4. 14-42
These results are quite surprising to me considering that I had the impression that the 12-60 was the sharper lens and the 14-54 is a tad softer. I know now, in the conditions that we tested it in, the 14-54 is indeed the better lens in terms of sharpness.
Having made all these comparisons, I need to highlight that these differences are probably very subtle. The difference between number 1 and number 4 is really very small. For the price and the weight etc, the 14-42 kit lens is a very commendable performer and I would say that it is nearly comparable to the HG lenses. It is lightweight and compact, and throughout the testing, focused well without any fuss whatsoever.
If anyone feels that their kit lenses are not giving them sharp photos, they should try to work on their photography technique and learn more about their DSLR, instead of upgrading the lenses.
Based on these studies, I can see now the only good reasons for upgrading to the high-grade (HG) lenses, ie 14-54 and 12-60, are for the performance of the HG lenses, rather than for the optics per se. The performance features of the HG lenses that I feel may be of benefit not present in the kit lenses are:
1. The HG lenses tend to have larger aperture, so may be better performers in low light.
2. The HG lenses are weatherproof.
3. They may be more durable - metal mount etc.
4. Better range of focal length, 12-60, 14-54 versus 14-42
5. Less distortion at wide angle ie. 14 mm
However, there is something I did notice with the 14 mm range of the 14-42 compared to the 14-54. It appears that the 14-42 14 mm is "wider" than the 14-54 14 mm. It seems that much of it may be due to distortion.
14-42 at 14 mm
14-54 Mk II at 14 mm