I swapped my 1 year old 999s for a 749R (which is now exactly 1 year old too) and did not miss the power at all , if anything the way the R spins up faster and higher is more of a buzz , I would say there is very little difference in speed and acceleration up to 120-130 , over this the bigger engine comes into it's own though.
The R has so many little differences from an S that make it special , in some ways it is even tricker than the 999R , the big tank changes the shape of the whole bike , not everyone's cup of tea but it works for me
As posted , the 05 model does not get the carbon bodywork even though it costs more , there may be some other small changes too , if there are any '04's left they may take a bit of finding , good luck