while I agree with SoP that you can get more and better power delivery by performing some changes (some of which I did), we are actually fighting what Kawasaki spent millions for. My personal conclusions: a bike this size is not for beginners, yet we get an electronic nanny, space and weight that could've been used for a CC or whatever, or another bit of fuel tank, and leaving the power delivery as it is, thank you very much.
I'll give you an example of another intake system on a bike that could've been great, yet it is insuferable: the K1600 from BMW. It has 1 butterfly (count them: one) feeding the six cylinders. It doesn't have an arrangement in parallel of 6, 3 or 2, because of cost, weight and building space, and it doesn't need butterflies in series because it's computed controlled anyway (with a stepper motor). Yet because the air filter seats so deep in the chassis, there is a long pipe and therefore it takes some time for the column of air to react when the butterfly opens. This translates in a feeling of complete detachment from the throttle input to the engine power delivery, regardless of how well the electronic is programmed (which it is). It's just physics.
Back to the C14, I like this bike a lot, but there were some decisions in the process of making it happen that I don't agree with.
But slow? compared to what, exactly? a Veyron is slow compared to an F-15.