For the pixelpeepers among you...
I made comparison shots between DA 35 macro, K 35 f/2, FA 31 Ltd and M 40 f/2,8 pancake (this last one especially for Heather, as this is the nearest you can get to her 43 ltd.)
All images are 100% crops that I assembled in one.
Center of image:
In the center of the image and wide open, the 31 ltd doesn't hold much of its' own, especially if you compare it to the 20 years older K 35. The M 40 is surprisingly good wide open, but all in all the DA is the clear winner...
When all four lenses are used @ f/2,8 it all boils down to preference I think, although I would still hand the cup to the DA. Surprisingly the 31 ltd isn't the winner, and I would place him 3rd. It is also the only lens that shows (little) CA.
Left bottom angle of image:
I compared the other three corners, and I couldn't notice any difference, so all four lenses are perfectedly alligned; no cold showers there...
The 31 ltd shows it potence in the angles: even wide open it comes in at a very decent second place (the DA is a little better.) If compared at the same f-stop, then the 31 ltd and the DA 35 make a draw, which is surprissing for the DA 35, given that it is used full open (the 31 ltd has a 1,5 stop advantage.) The M 40 is still very decent (comes to show that it is a very good lens!), while the K is still a little soft in the far corners (but still a very good performance too.)
Conclusion: some are not going to be happy in reading this, but I would place the DA 35 first, with the 31 ltd comming in close second. A little further away, third place would go ex aequo to the K 35 and the M 40...