BASICALLY
Fuck the RDV4 
Get a PM3 (you will be covered for everything)
once you have a tick in the PM3 box
Get yourself a Flipper 
Explanation below
I am a huge fan of the Flipper.
I also have an RDV4 AND an Easy,
FIRST and foremost
You “need” a ProxMark3, of any description.
if you have an Easy, you do not need an RDV4.
If you have an RDV4, you probably thought the same as me “its much more expensiver, so it must be betterer”
IT’S NOT
You want a Flipper, and you will have fun playing with the functionality, the size is great and more portable than a PM3 and laptop.
In time, I think the Flipper will be all that most people will need for basic read write functionality, but my opinion, its not quite there yet.
The flipper reads implants really easily, including xSeries, and better than either of the PM3s
LF
Reading and writing LF chips is simple, and covers most common modes.
Also emulates
HF
It also reads easily, BUT it cannot yet write to a Mifare Classic as easily as you would hope/expect. (Not as simple as LF side)
I’ll do a write up at some stage, but here is not the place to do that.
also emulates
This may be of use
If you want to keep it factory, thats the way to go
BUT
You are missing out on a bunch of other functionality and libraries, if you want that, try my link above
There is, and I have/do use it, personally I prefer Cable
phone-flipper
for the stablity and faster connection
Totally agree, I dont regularly carry it in my pocket, but have from time to time if I have a “reason”, But ALWAYS have it in my quick access pocket in my backpack.
Very
See my post above.
I can see some uses for it, but realistically you can do it all from your bluetooth connection screen emulation on your phone, and the phone is better, so I wouldnt call the Wear OS functionality a selling point, merely a capability.
Thats my 2 cents and I probably didn’t need to share, as the other guys covered it above, but I hope there was something of use in there…