PCM is the slowest digitized format of processing, Its only benefit was failsafe protection of unwanted signals thru FM modulation, but seems its not so good with JR and the recent Bandit crash. So......

PPM is the fastest, FM modulation.

For PCM to work it takes the PPM and digitizes it to a coded pulse which takes time. NO mystery why do you think its the same module for 20 years. IT's nothing but FM modualtion or PPM.

Consider the DX6 used an existing PPM JR TX and Spectrumized prior to transmitting to RX, it took FIRST PRIZE in being the slowest latency or TX delay to servos in the market and was unaccetable for most hardcore 3D heli work

Then comes the DX7 which no longer processes PPM and is straight thru digitized thus ALMOST the fastest latency but Airtronics PPM still is faster.(unbiased third party testing)

Then comes Spectrum modules, WHICH ONCE again digitizes the PPM, BUT on Spectrums own website they say that they can digitize the PPM and transmit FASTER than JR can digitize and send it PCM, so its an inbetween Hybrid faster than JR's own PCM digitizing capabilities, Which is still faster than hand/eye/muscle coordination IMHO.

A Heli pilot on Runryder has created a unique apples to apples elecronic test bed for ALL BRANDS TX Latency testing, unbiased of brand, creating a database spreadsheet, (PEOPLE send him HIGH dollar TX's for testing,) I can post link latter if interested, or just search TX latency.....