I just got my converted K100D two weeks ago, so I haven't had the chance to really put it through its paces yet.
I've noticed the hotspot more with my wide-angle lens, like the 12-24. But honestly based on teh way I compose my shots, the hotspot would not be that much of an issue with macro.
The only ones I have to show are these, taken with the DA 35 Macro and the D-FA 100 Macro, respectively. I'm still not quite happy with the processing of these:
With the 35mm:
Day 199: Self-Portrait on Flickr - Photo Sharing! Leaf Light on Flickr - Photo Sharing!
With the D-FA 100mm:
Day 200: Matching Shot on Flickr - Photo Sharing!