I finally tested my Spectra module (75mhz) with my 3PK last night. Everything worked like a charm on HRS (and digital servo) and in PPM mode (with analog servo). No glitching or anything out of the ordinary. I have been successfully using it with my 3pjs for over a year and a half.
Gotta love the crystaless mode (with XXtra receiver), but I agree that I am tempted to drill 2 holes in side for easy access to frequency dials. I agree that those slots on top must be for upcoming crystaless module from Futaba (or Novak)....for now I will remove when need to dial in a new frequency.
Love the new setup!!