ZL1 doesn't "walk all over" the G8x. In fact, they're evenly matched 6MT to 6MT. See video:
https://streamable.com/gpsmg0
That's the base, not the more torquey Comp.
Based on this, the GT500 is faster, but not by a significant margin. Again, not "walking all over" anything.
The G8x offers a complete and premium experience while performing just as well as those cars. It's basically a high-end BMW ZL1 with proper visibility, and now with AWD. As mentioned, you lose the great exhaust sound.
Beyond sound, not sure how you quantify "boring". All three will apply similar G forces to your body while accelerating, braking, and cornering. The G8x has very direct steering and corners flat (again, similar to a ZL1).
I think it'll be obvious which one works for you after driving them.