I played with a tab pro 8.4 at Best Buy today for about 20 minutes because I was wondering if it could replace both my nexus 10 and my nexus 7 (2013). I think I changed my mind, given the sheer amount of lag I saw on any type of scrolling whatsoever. Changing home screens, flipping through the app drawer, scrolling in chrome, you name it. It was like using a device from 2010.
Boo on you, Samsung! Now I gotta shop some more.