Guys I think I found the fix!!! I created an account just to post this.
I'm on T-Mobile coming from the note 5 and the performance after the first few days was atrocious. Apps super slow to load, keyboard lag, stuttering under load not to mention the phone getting really hot. Battery life has been solid for me. Better than n5. While the battery and heat is something that Samsung needs to address, the lag has been tremendously reduced and now all of a sudden my note 7 is the beast that I envisioned it should be.
THE FIX THAT WORKED FOR ME
Disable all apps that you don't use. I disabled svoice, s-health, lookout, and a couple others.
The biggest factor was changing scaling from Large to Small. I'm using TouchWiz and Google keyboard too. My phone is really hot right now but still butter smooth and blazing fast. Maybe a bug with scaling I don't know, but I promise, it feels like a new phone now. If this works for you, please share this message.