I just bought this last December the Fuji S5pro. Really nice camera. Excellent dynamic range. Better then Nikon D300 for example. But it is still a 6MP resolution (2x 6MP with different receiptions is not the same as 12 MP). In case you need a lot of cropping, you need to look for a 10MP or higher camera to get still good A3 prints.
Not that I think that more then 6MP are really needed in most cases for non-professionals or even for wedding photographers, but just to make you arware of this.
Handling is excellent, it has the same body and viewfinder as the Nikon D200. Only the menue structure is different (not as good as of the D200).
RAW-File size is huge and the S5 is still not really fast. So not the right tool if you need high fps.
Colours are very good. And you can use Zeiss ZF lenses with it of course. But I will sell mine again. I found a new "toy", which you will not believe (even I did not want to believe it...)
I have been saving up and I think I am going to go for the D300.
I had been thinking about the Pentax K20D and I waited for the Amateur Photographer review. This was out this week and although it was favourable, I think the Nikon has the edge. I also fancy the CZ and Voigtlander lenses that Robert White has for sale which are Nikon mount.
I'll let you know how I get on. I have been really biding my time DSLR wise but I think at last that the D300 is the one.