I agree it definitely depends on the rider but if you are getting jumpiness in the rear that sounds more like an issue with suspension setup than with the motor. When I first took the bike out on the track, I felt a little bit of that wiggle in the back end and all it took was raising the preload and messing with damping on the front so it wasn't sprung for a 120 lbs. Italian man and changing the rear so it wasn't sprung for a 250 lbs. dude with a passenger. She's all sorted now and is stable as my 1198 SP ever was deep into turns
With the S1000RR going from off throttle to on throttle always made me wince a bit, especially at higher rpms whereas on the 1199 I get on the throttle and it always feels smooth and predictable. Again, this is with stock fuel maps on both bikes and stock headers/pipes. I know jumpiness can be heavily mitigated with better fuel maps and a power commander.
I have never ridden an RSV4 but I would really love to get on one. I have always wanted to own a V4 superbike and the Aprilia is a sexy machine, barring that ugly ... exhaust that they ripped off from Suzuki of course but how hard is it to change a pipe?