Welcome redsail, I used to own an RC8, great bike but very different characteristics v an S1k. More powerful everywhere particularly at the top end and a lot more compact than the KTM, not quite as spacious but comfortable and practical. Then of course depending on which generation of RR you go for you'll far more electronic trickery than you're used to, a quickshifter etc etc. All models are superb but the latest 'gen3' version is the one to go for if you can afford it, I recommend taking a test ride on one to get a feel for how this particular inline 4 feels. What's your budget?