Welcome to the forum, Kev242! When I read your initial post I thought, I wonder why is he going from a S1000RR to 959? Then when I read it was an HP4, I was really shocked! Then after reading your explanation it makes perfect sense. Being a truck guy myself, (1199 Panigale) a lot of people don't realize that the bigger bikes don't always equate to faster lap times, and while they're faster on the straights, you have to stop them!! It took me a few seasons on the 1199 before I could improve on the lap times I was doing on my 848. Up until I bought the 1199 I've always ridden the smaller bikes. (748 - 749 - 848)I came from a HP4 to the 959 and can present my opinion....overkill! On the road it was so over the top as far as horsepower goes that if you ever opened it up you were WAAYYYY into triple digit speeds (MPH) in the blink of an eye.
My local track was useless for all of that power, it is very twisty and I only had about 3-4 seconds of WOT each lap. The bike destroys everything else down the straights, which is fun, but you will also carry that speed into the braking zones which gets a bit hairy with 30-40MPH more than you ever did before.
I find the 959 to be a lot more stable in braking, turn in, mid-corner, and it inspires confidence which for me is more rewarding than holding onto a missile.
If you get the chance go do the California Superbike School, they run S1000RR's and on tracks like NJMP where there are pretty good straights you can get to feel what @200HP on a 440lb bike feels like. Redline 4th, QS to 5th and the front will come right up!