Fuji X-20 compared to Nikon D50

Now, it depends on who makes the X20 sensor. I don't think it is by Sony, so it is likely to be an older generation design with the X-Trans CFA. This is why we do not see a significant high ISO improvement on the X20 sample photos so far.

In fact, X20 will need to go up to ISO 800 to achieve DR400%. A sensor's native DR is reduced with higher ISO. Where as X10 can do it with just ISO 100 in M size capture.