The 11098S's regular forged aluminium wheels have been replaced with lighter 17-inch magnesium alloy wheels from Marvic (16.5-inch wheels are an option for track use only), shod with Pirelli Diablo Supercorsa rubber. The stock 45mm Öhlins fork has been replaced with a 47mm K-Service item and the bike's wheelbase has been reduced slightly, in accordance with Ducati's World Superbikes machine.
The 1198RF's engine has been fettled by the Milan-based Desmolupo and features a host of performance mods to provide an additional 10-11 horsepower. Which probably means that for about five times the price of a regular Ducati 1198S, you get a machine that's a bit faster and handles a bit better. Now you decide if you want one...