The S5 Pro is a major improvement over the S3 Pro in its handling and build quality, and it makes for an interesting comparison with the Nikon D200. Definition at a pixel level is certainly no better, but the S5 Pro's tonal rendition is often superior, especially with portraits.
Also consider:

FEATURES
PERFORMANCE
BUILD QUALITY
EASE OF USE
VALUE FOR MONEY
FINAL SCORE

GOOD!

Reviewer: Salemme, Trois-Rivières, Canada

I have one, and I'm very satisfy! I got a D200 nikon too, and for sports, actions it's the best Nikon, but for the rest, I prefer my Fuji Pro5, excellent to photography birds ( programm range 400%), portraits, skin tone wow...Don't forget the Fujichrome programme, the colors of automn!!!

S5 pro

Reviewer: weeks01, inverness, uk

This camera is great,i have had one for the past year and i would not part with it.It is especially good for portraits.The screen for viewing back your photos is the poor part,it is not very clear

S3Pro

Reviewer: harrytsk, kuching, Sarawak, Malaysia

had been using S3pro for the last 3 years, Some exposure problems was solved, good tonal range, faithful colors,
battery life was short, burst rate 3 frames is terrible.
autofocus poor ,very slow especially AFS 80-200 2.8ED.