gs,
yes, DA40 is sharp right from f/2.8 - and, moreover, it is sharp all over the frame. So if the only thing you care of is sharpness, then you've got to go for DA40. But if you consider the other things too - like scene rendering - then stop where you are: DA40 has a damn awful bokeh. It is just plain bad. You'll struggle against this lens for getting nice smooth highlights blur and you'll lose most of the time. Though if you do the web-prints only limited to smth like 1024x680, then it may not be too much of an issue (that's why you will not see it here on PF where 99% of the pictures are resized down to 1024x680 or even 800x533), but even at full hd resolution (1920x1270) it is quite pronounced, let alone bigger prints.
Here's a 1:1 crop of a mid-sized 1920x1270 print:
There will be a hack of a learning curve with this lens. But if you master with it, you'll be a damn good photographer able to drive and get a decent shot from almost everything.
Oh, and it is really small lens. It is really really small lens. It is a damn small lens! It is so small that it will challenge your Freudian unconscious!
It is indecently, obscenely tiny! Every time I look at it I can't help but think of that famous Interstate 60 scene:
But yes, it is sharp. Moreover, it is uniformly sharp across the whole frame starting right from the max f/2.8 - and it also has a very good flare resistance.
Bottom line: do I recommend going for a DA40 (whenever SMC or HD)? No, I do not. But if you decide to give it a try, I will wish you good luck.
Zig
P.S.
Although I haven't got the FA43.