A lot of the Pros run fm due to the interferance that can occur on 2.4hz.
And before you say it yes you can get interferance on 2.4 as there are so many things that now run in the 2.4 range Ie bluetooth, cordless phones ,some mobile phone networks etc, and large metal strutures like shipping containers and steel portals can also interfere
At the worlds last year alot of guys where having interferance problems on 2.4 and it turned out to be a cordless phone causing it
