bdery, I also own both the DA40 Limited and the 18-55 kit, and made a comparison once. My finding was, that the DA40 is sharper and resolving higher.
To give the Kit the same sharpnes illusion as the DA40, you would have to crank up the Sharpening slider to the max (130%), to get the same level as the DA40 at 0%.
This comparison is not fully fair though, because 40mm and the wide end are the weaker spots in the kit's zoom range. Whereas at the 24mm mark, it excels almost like a prime, and the tele end is better than 40mm as well. But this may be only so in my setup, because I calibrated the AF at 55mm.
The DA40 has a slightly but visibly higher contrast (evident also from the histogram, i.e. shadows are darker and highlights are brighter.
The Kit has one adantage over the DA40 though: it has a better corrected curvature of field (=flat focus plane). So it's more suitable for photographing planar targets.
The Kit has one disadvantage, after some years it seems to develop slight fogging, even if treated properly, i.e. some bright stuff (not organic or dark, i.e. not fungus) is finding its way onto at least one surface. My kit is 5 years old (the non-WR version II).
Last edited by Frater; 11-14-2013 at 08:12 AM.