I can weigh in on this with a bit of insight. I've owned a Nexus 7 2013 for a little over a year and got a Tab Pro 8.4 about 1.5 weeks ago.
The good: Nice screen with a lot more real estate compared to the N7. Micro SD slot is always useful to have. Lightweight, even with my folio case. 8.4”, 16:10 AR is about the perfect tablet size.
The bad: Crappy speakers. Occasional freezes and frequent stuttering. I’ve even had some random lockups that restarted the device. More frequent app crashes/force close compared to N7 (HBO Go crashes at least once every time I stream with it using a Chromecast). Samsung’s insistence on using a physical home button and reversing where the back and multitask are compared to stock android. It also gets annoying accidentally touching on one of those capacitive keys when holding the tablet in landscape mode.
The ugly: The N7 2013 feels faster and runs smoother, regardless of what the paper specs state. Touchwiz + 1600p is not a good combination in its current software state. Touchwiz just sucks in my opinion. I didn’t like it on an S3 phone I used to have, and I like it even less on this tablet. The system settings menu is a special kind of terrible only Touchwiz knows how to achieve. It’s sad that Samsung is OK with impressive specs being hamstrung by such a mediocre user experience, but it is what it is unless you’re OK with voiding warranties to put something like CM on it. Will the 5.0 tablet Touchwiz be better optimized? Will it come at all to this device? Who knows.
Now, the important part: I’m keeping mine because a $200 tablet at that size and resolution with a micro SD slot is hard to come by. Even with the negatives, it’s still a great value for $200. Videos/reading/comics/web browsing look great on it. My N7 has been fine, and still is, but 7” is a little cramped for many things outside of books. Most of the Touchwiz user experience gripes go away once you’re in an app too, but it’s still disappointing knowing that Touchwiz is always lying in wait to slow the tablet down, or rear its head because you accidentally brushed against a capacitive button or left some superfluous feature enabled.
I still recommend it though at that $200 price point.