Large smartphone, smaller tablet, or one of each?

I'm buying a mobile device to replace my desktop i ended up selling and I'm wondering is there enough of a performance difference between a 5.7" phone and 7" tablet that I should get the tablet instead? I'm just talking phone versus tablets in general. Is there some compelling reason to get one of each? As in, practicality and mobility in the smaller size of the phone but the phone lacks enough power for there to be a good excuse to spend money on a tablet. I have noticed some websites load better on tablets or will load on tablets but won't on phones. I'm assuming this is because the tablet has a better CPU and such right?

Look at the specifications. From what I can tell, tablets seem to have largely stagnated in terms of development.

This is the phone I recently got and for $300 after instant rebates, it's hard to beat:
http://www.lemall.com/us/phone/leeco_le_pro3/index.html
About the only tablets that will beat it in performance are the high end Intel ones that will cost way more than $300.

To my knowledge (and I haven't looked into the phone/tablet market recently because I've been focused on the desktop) there are phones that have more powerful procs and better gpu than tablets and vice versa. The main difference is screen size. For instance tablets allow for you to add VIOP services/calling ability to be used as an oversized phone. The word "phablet" was a buzzword a while ago for an oversized phone/undersized tablet. The average phablet was sporting a 7 inch screen (8 is usually where a tablet starts at)

The performance differences you mentioned are likely due to longer development periods for tablets. Phones are (IMO) rushed to market as fast as they can be and often haven't gotten the TLC needed for optimization. There are speed tweaks and optimizations that will make an android device into a buttery smooth example of what a user experience should be, and I've seen these things take mediocre hardware and change it into a real powerhouse.

What I would be conscious of when choosing either phone or tablet or both, is the size of the development community. The Samsung devices for instance have one of the largest user bases and consequently one of the largest development communities. What does that mean for you? More cool stuff like custom roms/kernels and more opportunities for support when trouble arises. A decent custom rom will make you want to spit upon the heathen that loaded a stock rom at the factory , but you should listen to the warnings about voiding warranty because some manufacturers take that pretty seriously while others won't mark your modifications against you.

I was thinking s tablet might be a better contender for things like games or other multimedia tasks at home but I can see that phone these days seem to be just as powerful as the tablets I've had. Had a 2012 or 2013 galaxy tab and my brother's LG Stylo 2 Plus feels just as powerful. Apparently I've been out of the mobile game too long.

S pen enabled tablets aren't for gaming, they're for drawing as in art or digital notetaking. Sadly, the most recent S pen tablet, the Galaxy Note Pro 12.2, is over 2 years old.

Phones are abysmal for actual browsing, period. I could care less how fast it is, the screens are simply too small to make it truly enjoyable. On top of that, to want to make a phone be everything from your camcorder to your gps, to your games, etc., is a waste of time. There are plenty of tablet choices that blow phones out of the water as far as 'ease of use' per se. Phones have tiny keyboards and all the headaches that go along with it when you suddenly have it trying to do 50 different things. I would say, buy a nice phone like nihao did, making sure you can root it, and grab a nice tablet for the immersive stuff, keeping the phone what it was meant to be; an address book with a dialer. You want nice pictures or video, buy a camera. I got enough of android rammed down my throat with my phone so I would never own a droid tablet myself.

Plasma Mobile (KDE) is now available as an OS for the nexus 5 and the one plus one btw.
https://plasma-mobile.org/