The 18-55mm kit zoom is actually a very good lens and at its wide end gives very little away in terms of max aperture.
There have in effect been two reviews of the lens in its Mk 1 and Mk II guises by Popular Photography -
review of the Samsung clone
18-55 Zoom -
PopPhoto.com seems to have dropped their very useful SQF (Subjective Quality Factor) charts from these web versions -
scans from the magazine -
and the more current 18-55 AL II version -
- from their review of the Pentax DA 18-55 AL II -
The current Mk II is a slight improvement over the original which was already well praised -
so the 18-55mm Mk II kit zoom is somewhat of a bargain.