Yep I went and removed all the stock servos and installed HS-55. [:'(] I took my time and got all the wires neatly routed and secured.

The servos plugged right in and I used the original control arms. The swashplate now is a bit off from its flat and level position, but 3 turns down on the front clevis got it really close. It still needs slight adjustment on left and right.

I spun it up to full power while holding the model (carefully!) in one hand. This allowed me to finally nail down the throttle and pitch curves in my DX6. I believe its ready for some sliding and hopping tests in the clubhouse tonight

Although I can't say for absolutely and for sure, it does appear to these nOOB eyes that yes indeed these HS-55 servos are superior in response speed and strength.