While 650 is lower than the 707 horses corralled by the Dodge Challenger Hellcat, the ZL1 will almost assuredly be faster around a track. Perhaps a more interesting comparison will be between the 2017 ZL1, the latest Corvette Z06 that also boasts 650 ponies, and the 640-horsepower Cadillac CTS-V. It'd be an all-GM battle of brands.
If you've got lots of time on your hands, feel free to peruse the complete ordering guide from www.camaro6.com here (pdf link). There's more there than just the final power figures for the ZL1's supercharged 6.2-liter V8 inside (do a search for the word 'NEW!' in the document). Let us know what fun little tidbits you find.