The MX-3FG uses FHSS-2, it's newer and a little faster. The newest is the MX-3X and uses FHSS-3. FHSS-2 is not backwards compatible with FHSS-1 however some FHSS-3 systems are BC with FHSS-2.
Ohh... so how much difference can the FHSS-1, FHSS-2, and FHSS-3 make? If there are 15 people using the same brand same, same model FHSS-1 radio, will they have the slightest chance to glitch?