Hmmm........the performance difference might be very small, Ducati only claimed the r had 3bhp more than the s but the r had more goodies.
Carbon body work, ohlins front forks, bigger bore shorter stroke engine,
I rode a 998s and feel wise it didn't ride a lot different with the showa nitrided forks but the engine just didn't have the grunt of the r, maybe the s I rode was a poor example.
Did a you have a go on mine and I'll have a go on yours swap with someone years ago who owned an MV f4 1000. They also had a 998s and it was killing them to know if the r was a big step up from the s. Their view was there wasn't a big difference, certainly not enough to justify the big £££££ it would cost them to "trade up"
Incidently I thought the MV was a beast, like sitting on top of an F1 car engine but a bit of bus handling wise
If the OP is who I think he is then maybe owning a r is a long held itch that needs scratching.
Ray