For the record, my Note7 is an Exynos variant. I wouldn't say it's lag-free, since all phones lag at some point, but so far, I haven't really experienced any serious performance issue. According to the article, the test was done on a Snapdragon-powered variant. Not deriding the 820 here, but it seems to be theme with Samsung devices, that the Exynos would perform better.
However, the only thing that's really bugging me is the keyboard lag in SwiftKey. It's terrible, especially for a fast-typer like me. Not sure if it's the phone or the keyboard, since the phone has performed quite well in other tasks.
I'm going to wait a bit for more Snapdragon Note7 users to share their experience, but my personal experience with my Exynos unit is alright.