Several weeks ago I purchased an FA50/1.4 here on the forums and was absolutely floored by the quality. Then a DA40 came up for sale shortly after, which I promptly purchased. The DA40 is one heck of a sharp lens and renders MUCH more naturally than any lens in my collection. As for other image parameters, I haven't used them long enough to judge. My gut tells me that the DA40 is better right across the frame but I have yet to quantify that.
In our case, my wife has a K-m so having two lenses so close is a no-brainer. And I get to play with them both, as much as I want
Anyway, each lens has its own character (which I have yet to explore) so they would be suitable in different circumstances.
Doesn't really clear that up now does it lol.
- Andrew