Really Nathan? Not heaps of KDX 250's around and certainly not lots of parts available. Forks and brakes aren't a patch on an IT200. Can rebore the Yam. I reckon IT200 by a mile. Any model is fine for vic enduros, even the disc brake ones.
There's no question that the IT has better brakes and suspension. But the KDX250 motor is a magnificent thing, while the stock IT200 motor is all midrange without managing to be all that impressive even there. Plus the IT's riding position is cramped.
More importantly, you can never get away from that vague IT steering.
And the KDX's brake and fork woes are easily fixed with a KX front end conversion.
The IT200 is a great bike. But I prefer the KDXs by a considerable margin.