I'll leave the handling comments to what others have already said but I understand your point. But what the hell were you expecting racing a Hellcat? It has 700+hp and you don't even have 500hp.
Anyways, you are disappointed in the numbers for the ZL1. Let's put things in perspective.
From C&D '15 HC A8:
http://www.caranddriver.com/reviews/...at-test-review
Standing ¼-mile: 11.7 sec @ 126 mph
From MT: Another A8
http://www.motortrend.com/cars/dodge...at-first-test/
Standing ¼-mile: 11.7 sec @ 125.4 mph
Now according to GM press numbers (which have been conservative the last few cars they have released):
Quarter-mile in 11.4 seconds at 127 mph
Let that sink in for a min. Not so much the times as the MPH. Then let it sink in that the HC is undertired and has horrible issues launching with anything short of DRs/slicks. So no the new ZL1 will not get it's ass handed to it in real world driving. Most likely ZL1s will neck and neck and it will come down to who is the better driver. And stock to stock, expect the ZL1 to leave the Kitty on the line spinning.
If you wanted to blow the HC out of the water on the track, accept the reality. It takes a hell of a lot power, weight loss, and/or pure drag tires to go that much faster. We are very much at the limits of what a RWD car can do and still meet federal safety and emissions requirements. Dodge knows this all to well. They had to detune the HC to meet emissions. And I got news for you, they aren't find anymore power without a DI swap which they have no money or development in so far. There are rumors the HEMIs are gone after 2020. FCA has abandoned small cars and CAFE penalties just increased 150%. FCA has no trans development of their own and are stuck with the 8 and 9 speed units ZF developed. To meet CAFE targets, FCA has to radically change their approach. All this means you will not see the HC beyond the current gen platforms in the sense it is now. Smaller, lighter cars with turbo 4 and turbo 6s may be all they will offer in the new gen. Maybe a smaller more efficient turbo V8 could become the new HC then, but the future of Dodge is bleak at this point.
Ford is the real threat if they are working on a TT V8, but we have yet to see what's coming for the ZR1 too. Also Ford still hasn't said anything about a GT500 at this point. Which is strange considering the 6th gen was released in '15 and here the Camaro just came out last year and already has ZL1 revealed.