Welcome Oli, I am not a 1098 or 848 owner, but going on what folk say, the 848 is the better bike for handling etc, I am sure some will come on and say the opposite, but I can name a fair few who will agree with me.
As you have not ridden a Duke before, I would suggest a trip to your local dealer and organise a test ride, you will not be disapointed.
Regarding servicing costs, they are a lot cheaper than they used to be on the 748 / 916 range, some one will give you more details on that though.
Chris
