Prefer version 5 (v5), essentially you get another machine with full support from TP-Link, cloud and mobile management, auto reboot, support for openwrt firmware, and many more. However, it works fine with a Vodafone 3G USB dongle that I have.

Good as a machine, it just doesn't do what it said! Although recognized by the tp link app, I couldn't activate it in cloud management, something that, even though it appears as a tab, seems to not work even with a static IP!

I have been using it in a residential photovoltaic system to record online data for the past 4 years. I have not encountered any problems so far in an outdoor environment, environmental conditions

Far away!!!
I have had the product since 13/7/2017.
I bought it to connect it with a 4g modem dongle stick, the k5160, provided by Vodafone. This is actually the ONLY modem that Vodafone provides worldwide!
It doesn't work at all! They don't cooperate, it doesn't even recognize it because it requires a special driver.
I contacted the official support of tplink and they sent me a program with which I had to create the driver MYSELF. What's even more unbelievable is that the program is only for Windows XP! Although I finally tried it 4-5 times, the program still doesn't work!
So stay away from this product and especially from this non-existent company with zero support!