I do not agree but I do not know Teltonika. I bought these routers first because of their size and then because of their specifications because in my country a few years ago it was forbidden to bring any type of router and they were easily camouflaged among the things in the suitcases with a little aluminum foil to avoid X-Ray inspection.
I have 2 AR750 along with an AR750S and they work fine for me, I just have to know their limitations, but I have wifi and share files in a big house with no problems, all routers with wifi 2.4Ghz and 5Ghz, guest wifi and I used, but already no (my teenage daughter used to ate all the LTE data in one bite lol), another separate 2.4Ghz SSID with a separate LTE device on a second WAN set up “just” for WhatsApp for my family because unfortunately I don’t have 24-hours of internet in my country.