bought E398 from this seller, and it support tp link MR3020, and getting such speed.
http://www.speedtest.net/my-result/2909860969

http://www.speedtest.net/result/2909860969.png

And result when i plug in to USB 2.0 port.

after connected, i need to wait few minute before i am able to online.
not sure what wrong, this also happened when i plug into 3G router.
after installed driver, my USB3.0 port is not able to detect this modem, but usb 2.0 is able to detect.

http://www.speedtest.net/my-result/2909879783
http://www.speedtest.net/result/2909879783.png

Driver i mean is internal software from modem. it got 1 virtual drive and i install software and driver from it.

after perform firmware update to modem, everything is ok. 3G router able to connect to LTE in a minute.