I'm not sure why there is any conflicting info unless it's a really old thread. The actual info has been well known for a while now.
The
300A and
300B RCs both have the same power output for the control signal. It's only the
300C version of the RC that has reduced power. If you don't do any very long range flights, you probably wouldn't notice a difference with any of the versions in that regard.
The 300A RC has the
DaVinci processor and USB 2.0. B and C don't have the internal video processor, but do have USB 3.0.
The video transmitter (for FPV) is in the quad itself, and the power for that has been reduced with each new version of the Phantom. First reduced by 18% in relation to the original and then later by 30% in relation to the original.
Here is more info from
@GadgetGuy
Old Motors vs. New Ones
The
GL300A controller has a frequency range of:
2404.00000000 - 2480.00000000 and a
power output of 0.380000 Watts
The
GL300B controller has a frequency range of:
2404.00000000 - 2480.00000000 and a
power output of 0.380000 Watts
The
GL300C controller has a frequency range of:
2404.00000000 - 2470.00000000 and a
power output of 0.3030000 Watts