OK, got a ZTE modem after all, not even a 4G one, I came to the conclusion that I just don't need 4G speeds as the most demanding thing I do on the Internet is watching videos
Now I have a 14.4mbps 3G plan (is ten bucks less per month) and a 7.2mbps USB device, the combination works fine so far. Ping is about 50ms, speed is always between 2.5 and 5mbps down and between 1.5 and 3mbps up, love it
No more interruptions on Youtube videos, let alone anything else.