AHP

The Z06 is more raw and the powerband is more peaky. The ZR1 rides a lot nicer; I do agree with above that the ZR1 is slightly more GT than race car. It is slightly heavier (though still very light in today's standards) so it's not quite as zippy feeling. However, the ZR1 still a precision tool that carves in the corners. Power-wise, they are worlds apart, IMO. The LS9 makes incredible TQ everywhere in the powerband; it effortlessly pulls through any gear at any RPM, largely because the blower makes nearly full-boost even with little throttle application. I much prefer the gearing on the ZR1 as well; the tall 1st gear is great on the street (makes drag launches a little tougher, but still very attainable) and it rips up top with the shorter 5 and 6. The biggest distinguishing factor (for me, at least) is the power potential of the LS9 with simply bolt-ons. For the cost equivalent of... ..say long tube headers for the Z06 --- you can add 100+ WHP to the ZR1 with absolutely zero sacrifice in driveability and reliability, and that is just the start. And with simple bolt-ons, the TQ curve becomes absolutely violent (in all the right ways) and is simply not achievable by an NA LS7. The nearly-instantaneous, stump-pulling, peel your face off TQ is something to be experienced.

Stavesacre21

I haven't owned a carbon Z, but I have owned a 427 convertible as well as a ZR1. The differences in the engines are quite substantial. Power delivery from the LS7 is more linear, and does require your run it up to 4K+ before it feels explosive, whereas the ZR feels insane at just about anything above 2K. As others have mentioned, there is a very slight bit of SC lag, which surprised me when I first stabbed the throttle on the ZR, especially being used to that 4K instant responsiveness I mentioned on the LS7.

Also mentioned above, the gearing is much shorter on the ZR (especially when comparing to the even-longer-than-the-Z's 427 gearing), to the point that in daily CASUAL commute, I rarely use 2nd or 4th unless really getting on it. Fuel economy takes a noticeable hit, especially since 5th and 6th are geared extremely short. We're talking a 2500 RPMs in 6th gear going only 70. The ZR isn't made to be a cruiser, but then again, not too many are using it to parade around at loftily low RPMs.

At the end of the day, the LS7 felt a little more "engaging" as it does require you to keep the engine on a boil where as the ZR lets you get a little but more lazy and let the insane TQ make up for any shortcomings. I sold off my 427 because the LS7 just made me a little nervous with it's head issues (some even after repair) and I was just ready for a bit more TQ. I expected the ZR to be more one-sided on this win between the 2, but the honest truth is that it just barely gets the nod from me. You can't lose on either tho.