I've used all three with the
Mavic 2 Pro and they each have their advantages and disadvantages although for me, my preference is the integrated controller. Though I live in Scotland where we rarely see the sun so viewability of the screen is not really an issue.
The phone is the most portable solution since you can use the smaller controller design and you'll have your phone on you as well. Phones also usually offer a larger screen than the 5.5in on the RC2 which can make it a bit easier to frame shots and see where the drone is looking.
The tablet is clearly a lot less portable than the phone and can be awkward to carry with the drone if using a small camera bag however it offers a fantastic view of what the drone is seeing and can make it much easier to frame shots or video.
The RC2 has a small 5.5in screen which can be a bit trickier to use and the controller unit is quite a bit heftier since it's basically a phone and controller stuck together and can't be separated. I'm not up to date with the RC2 so I don't know if it's possible to sideload applications or any limits similar to that. However its big advantage is the convenience since you can simply power on the controller, click connect and it's good to go. With the phone or tablet solution, you need to get the controller powered up, get the USB cable out, place the phone/tablet onto the controller, connect the cable, unlock the device, open the app, connect to the drone and the same in reverse. That sounds like I'm exaggerating the sequence but for me when I'm using the drone out a walk or cycle I really value being able to get the drone quickly up and back away again.
In terms of the
Avata vs the
Mini 4 Pro it depends on what you want from the drone. I have the original
Avata and it's incredibly fun to fly feeling like a little guided rocket where I can take shots diving into forests and similar I would never do with the normal drone. For me though it's a bit of an expensive novelty and given the choice again I wish I hadn't bought it since it rarely gets any use. The Mavic is a really good platform for general videos and photos so it's had plenty of use however just to stress that is just my personal view and there's clearly plenty out there who enjoy the Avatas and FPV flying.