FWIW. I recently tried a pair of Hitec HS-65HB servos in my x468 Medium Camera Mount and was not happy with the performance---a fair amount of "twitching" and not very smooth motion. I was also using a small point & shoot camera (Canon A620). I switched to a pair of Futaba S3102 servos, and performance improved noticeably. The twitching is mostly gone and the gimbal moves very smoothly. I attribute the improvement,in my case, to the increase in torque (51 oz-in vs. 25 oz-in). The speed of the Futaba is a bit slower (0.25 sec/60* vs. 0.15 sec/60*); but for me, speed was not an issue---it was moving the 10 oz. camera effectively.
I did have to cut out the servo holes in the mount to accommodate the slightly larger servo, but a few minutes with a Dremel took care of that.
Also from my reading (not experience), prevailing wisdom seems to be that analog servos perform better than digital on the Naza.
Jack