FD19 has increased my 3G data speeds dramatically. I tried all of the other modems, and I was consistently getting less than 250kb/s, and sometimes as low as 30kb/s on SpeedTest.
I've now been reaching up to 1.6mb/s using the FD19 modem, which is a 600% increase of data speed. There weren't any planned data upgrades in my area according to the Sprint Network Enhancement Map. I'm on Long Island, New York.