I don't know anyone running Jardines with a Carpenter kit. I've heard of people getting the 240 kit, and being disappointed because they got less than 200 hp, because they left their exhaust on it. People can do what they want, but if I'm spending money on hp I'm going to run the components the kit calls for.
Not sure what you expect to feel at a steady speed. The motor (especially after being modified) is smooth as silk. It's not a big rumbly paint shaker like an American V-8 in a Boss Hoss. Like I mentioned before, below 4000 rpms it behaves like a stock R3 (which is plenty powerful), so for that 2 tenths of a second it takes to go from whatever rpm you're at to 4000 it pulls like a Rocket does. After that, you'd better have your body forward, and a tight grip, because she will accelerate like it's trying to rip out your arms, and detach your body from your soul.