The sp100 is a different action than the sp200. I like the 200 MUCH better. Of the three - the Yamaha has the "darkest" most classical tone, the Korg has a "brighter" more pop oriented tone, and the Roland is somewhere in between the two.
If you can stretch your budget just a bit - check out the Roland FP3. It's got better sounds, better action, smaller size/weight ratio and built in STUDIO drums and accompiniments.(selectable of course)
I like the FP3 better than the others in your lineup for straight ahead piano sound & action.....but when you add the session drums and backings - it's a better value.