Any advantage, bigger surface area, less pain etc
pain means buy better shoes
Using pearl izumi vagabond, quite a stiff sole unit
Very happy with mine, they seam to work as well or better than ones with a bigger platform. Unsure about easing pain, the cage is more for locating the cleat.
I have the XTR version and really like them - bit of platform means they are dead easy to clip into and there's a much bigger contact area than on non - platform ones.
As for easing pain, I find them to be loads comfier - I used to get hot spots on my feet on long rattly descents, but not any more. I don't think the 530s have exactly the same contact area arrangement, but it looks pretty similar.
Got them on both bikes and even put some on road bike so I can wear winter mtb boots. V. good, easy to clip in and you can rest your foot on them if you need to.
I've got some. They're fine, typically bombproof SPDs that just work, as you'd expect. Only issue I had was the bigger platform around the clip mechanism actually makes some shoes difficult to engage; they were Shimano shoes at that, weirdly enough. I had to shave a bit off the soles to get them to work, not a big deal.
No idea if they'll help though, I never got any pain with my normal SPDs either so can't comment on that.