ORIGINAL: Flying Geezer

I can answer some of your questions.

1. Futaba apparantly believes that switching frequencies 500 times per second doesn't let you stay on a dirty frequency for very long. I believe the other manufacturers switch only when interfered with.
The U.S. military also uses a variation of freq hopping for their communications as it is hard for the enemy to follow and hard to jam. With compressed burst transmissions the entire message can be sent before the enemy can even detect the signal let alone track it's origin.
To the best of my knowledge the Spektrum doesn't change freqs even if jammed. How would the TX know it was blockked and therefore change?

2. I don't know that they do.
Range is slightly better perhaps but more likely just improved components. Also 5.8 GHz is becoming the new optimum phone band.

3. Because they are not limited to just 50 channels where someone can turn-on on your frequency. Also because the ultra-high frequency is almost impervious to things like ignition noise, and because devices operating on these high frequencies also run at low power. Not so on 72 mHz, eliminates distant interference.
All true.

4. Think of the speed of radios like you do the speed of computers. 2.4 gHz is about 33 times faster, if my quick calculation is right. Your receiver get about 2.4 million commands per second.
Nope. First 2.4 GHz is 2,400 million cycles per second which is the operating frequency but not the command repetition rate (much lower). The signal repetition rate is the same a 72MHz radios when modules are used. The Main encoder board inside the TX determines the repetition rate and doesn't change just because you plug in a module.
5. Longer antennae are not possible at 2.4. Antennas are a tuned device, and the proper length of an antenna is inversely proportionnal to frequency. The higher the frequency, the shorter the antenna.
While correct about antennas being inverely proportional to freq you CAN still have a longer antenna but length is more critical in this freq range. Instead of a 1/4 wave antenna you could have a 1/2 wave or other multiple. There is a practical limit of course and for FASST Futaba would also want you to maintain the 90 degree difference.
6. A whip antenna is just too long to work.
Nope. A properly made whip or "spike" andtenna could be used. Difficulty again occurs at higher frequencies where connectors become more critical. If you have ever ran a TDR (Time Domain Reflectometer) on a long length of antenna coax it would show you every little bump(connection) in the line as well as where the coax has been pinched or damaged. Connecting the RX antenna to the whip/spike would be the tough part to do properly.

7. Because there are not channels, they just keep changing frequency anytime they interfere with each other, and they do it so fast, you don't even notice. Most of the non-rc devices switch frequencies too. It's like an insame game of electronic bumper cars.
The FASST systems change freqs constantly without waiting for possible interference. Don't care if there is interference as they are already gone. IMO the Spektrum system is considerably more susceptable to interference but have been doing OK due to dual freqs. Chances of jams on both freqs are minimal.

Not meaning to debate Flying Geezer but his post gave me a chance to present some additional views.