The ZX6 and firestorm are completly different beasts.
As Kaz said you have to wring the neck of the 6 like you would any other four, it is lighter and will go round bends quicker than a standard storm.
In a straight line the storm is prob quicker up to speed , tho the six will have a faster top end i suspect.
That said, if good rider on a storm can stay with the 6 thru the bends the zx will struggle to keep up coming out the other side, its all about torque. see?
Having ridden modern IL4's i think they are pretty clinical, the engines feel well contained within the boundaries of the chassis.
I dont know how others would describe the engine on their storm but i would liken it to having a "hand Grenade" in your right hand. Or even like poking a tiger in the eye with a stick and then jumping on its back and saying "c'mon giddy up".
Riding slowly on it feels like you have it caged up snarling to be let out

, and when you do let it out, boy does it like to run

(albeit not very far with the minute tank range hahaha)
Couple of words of advice.........
If you have the extra cash get the front end reworked(prefferably by roger ditchfield).
For peace of mind change the CCT's or have em converted to manual( essential really )

.
But the main thing is treat it with respect to start with bro, explore the bike carefully while you are gaining valuable riding experience and dont go cracking the throttle open in first straight away unless u wanna good look at the sky or end up on your back.
If you take the time to do this then you will find your storm is a great bike to ride . Gel with it first and it will reward you every time you go out on it.
Enjoy, and welcome to the world of the big twin.
John'o